Liquid crystal display device and fault repairing method for the liquid crystal display device

ABSTRACT

There is provided a fault repairing method for a liquid crystal display device capable of repairing simply a disconnected portion when a disconnection fault occurs in a display panel. For example, it is on the assumption that the disconnected portion is present in a data bus line. Disconnection repairing contact holes that have a width larger than that of the data bus line are formed in a protection insulating film on the data bus line on both sides of the disconnected portion respectively. Then, a laser CVD film (metal film) for covering inner surfaces of the disconnection repairing contact holes is formed by the laser CVD method, and then respective laser CVD films are connected electrically.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an active matrix type liquidcrystal display device and its fault repairing method.

[0003] 2. Description of the Prior Art

[0004] (Prior Art 1)

[0005] The liquid crystal panel of the liquid crystal display device hasthe structure that is constructed by sticking two sheets of glasssubstrates, i.e., the TFT substrate on which TFTs (thin filmtransistors), etc. are formed and the CF (color filter) substrate onwhich the color filters, etc. are formed, to oppose to each other andthen sealing the liquid crystal between them.

[0006] A plurality of gate bus lines, a plurality of data bus linesintersected with these gate bus lines via the interlayer insulatingfilm, storage capacitance bus lines for crossing respective pixel areasthat are defined by the gate bus lines and the data bus lines inparallel with the gate bus lines, and lead wirings for connecting thegate bus lines and the data bus lines to external connecting terminalportions respectively are provided on the TFT substrate. The TFTs areformed in vicinity of the intersection points of the gate bus lines andthe data bus lines. The drain electrode of this TFT is connected to thedata bus line, and the source electrode is connected to the pixelelectrode.

[0007] Meanwhile, the reduction in the fabrication cost is the importantsubject in the liquid crystal display device. In order to reduce thecost, first the improvement in yield of the production is stronglydesired. As the cause to lower the yield of the production of the liquidcrystal display device, there are the disconnection occurred in thewirings such as the gate bus lines, the data bus lines, the storagecapacitance bus lines, etc., the interlayer short-circuit between thesewirings, and the like.

[0008] For example, in case the driver circuit is connected to the oneside of the gate bus line since the disconnection occurs in the gate busline, such display panel is the defective unit. In order to repair thedisconnection occurred in the data bus line, there is employed therepairing method of providing the repair wiring around the display areaand then connecting the disconnected data bus line to the repair wiringby the laser welding such as the YAG laser welding, etc. However, thereis the problem that the detailed wiring routing becomes complicated inpanel design.

[0009] Also, as other cause to lower the yield of fabrication of theliquid crystal display device, there is the interlayer short-circuit(line fault) in which the gate bus line and the data bus line areshort-circuited or the interlayer short-circuit in which the data busline and the storage capacitance bus line are short-circuited. In theprior art, there is employed the repairing method of providing therepairing wiring on the outside of the display area, then disconnectingthe short-circuited area of the concerned bus line and connecting theconcerned bus line to the repair wiring by the laser beam when the linefault occurs in the display panel. However, according to this method,the number of repaired wirings (the number of bus lines) is limited bythe number of repair wirings provided on the outside of the display areaand the repairable number in the block. Since the unrepaired line faultstill remains if the number of line fault is larger than the limitednumber, there is the problem that such display panel is treatedinevitably as the defective unit.

[0010] (Prior Art 2)

[0011] In recent years, the larger size and higher definition of theactive matrix type liquid crystal display device make progress. However,with the progress of the larger size and higher definition, the wiringload capacitance is increased and also the horizontal scanning time isshortened. Therefore, the resistance value required for the wiring mustbe lowered much more. In particular, the serious degradation of thedisplay quality such as the lateral crosstalk, etc. is brought about bythe increase in the resistance of the storage capacitance bus line toprovide the potential to the storage capacitance electrode. For thisreason, the counterplan is applied by supplying the voltage from bothends of the storage capacitance bus lines to reduce the time constant.However, in such structure, there exists the portion at which theelectrode that is provided to connect collectively the storagecapacitance bus lines intersects with the gate bus lines.

[0012]FIG. 1 is a top view showing a configuration of the liquid crystaldisplay device. In this liquid crystal display device, the liquidcrystal is sealed between the TFT substrate 18 and the CF substrate 40and the area in which the liquid crystal is sealed acts as the displayarea 38. At the end portion of the TFT substrate 18, the gate bus linesand the data bus lines (called also as the drain bus lines) arecollected as a plurality of gate bus line groups 48 and a plurality ofdata bus line groups 50, and connected to the TAB substrates 44, 46respectively. The TAB substrates 44, 46 are connected to theprinted-wiring board 42.

[0013]FIG. 2 is an enlarged view showing the portion encircled by abroken line in FIG. 1. The gate bus lines 10 are connected to the gatesof the TFTs 30 formed in the display area respectively. End portions ofthe gate bus lines 10 are connected to the gate terminal (TAB terminal).A plurality of pixels are arranged in a matrix fashion in the displayarea. Each pixel is surrounded by the gate bus line 10 and the data busline 34, and the TFT 30 and the pixel electrode 32 are formed everypixel. The source electrode of the TFT 30 is connected to the pixelelectrode 32, and the drain electrode is connected to the data bus line34. The storage capacitance bus lines 22 that are formed in parallelwith the gate bus lines 10 by the same steps as the gate bus lines 10are formed in the central portion of the pixel area. Also, in order toprevent the destruction of the TFT by the static electricity, the gatebus lines 10 are connected to the guard ring 26 via the protectionelements 28.

[0014] The storage capacitance bus lines 22 are connected to the storagecapacitance bus line general electrode 16 via the storage capacitancebus line connecting electrodes 24 and the connecting portions 24 a, 24 brespectively. The storage capacitance bus line general electrode 16 isformed by the same steps as the gate bus lines 10, and the storagecapacitance bus line connecting electrodes 24 are formed by the samesteps as the pixel electrode 32. The storage capacitance bus linegeneral electrode 16 is provided commonly to a plurality of storagecapacitance bus lines 22 and is connected to a plurality of storagecapacitance bus lines 22.

[0015] In the meanwhile, the gate bus lines 10 are provided to intersectwith the storage capacitance bus line general electrode 16 via theinsulating film. FIG. 3 shows the intersecting portion of the gate busline 10 and the storage capacitance bus line general electrode 16. Ifthe short circuit occurs in this intersecting portion due to the staticelectricity, etc. during manufacturing steps, the line fault is broughtabout in the direction along the gate bus lines.

[0016]FIG. 4 is a view showing another configuration of the intersectingportion in the prior art. In the configuration in FIG. 4, the gate busline 10 is separated into two branch portions 10 d, 10 e in the portionat which the gate bus line 10 intersects with the storage capacitancebus line general electrode 16. In case the short circuit occurs in theintersecting portion due to the static electricity, etc. duringmanufacturing steps, the short-circuited portion is electricallyseparated by cutting off the short-circuited branch portion by the laserbeam, etc. after the short-circuited position is checked by theinspection using the pattern recognition. Thus, the gate bus line 10 isrestored to the normal gate bus line.

[0017] However, all the short circuits that occurs actually cannotalways be recognized by the inspection using the pattern recognition.Therefore, even if no problem exists in appearance, there are many caseswhere the very small short-circuits are present. In addition, if theshort-circuit can be detected by the electrical test, it cannot be foundthat which one of the branch portions 10 d, 10 e should be cut off. Thiscauses the extreme reduction in the repair rate (relief rate) of theshort-circuit fault.

[0018] (Prior Art 3)

[0019]FIG. 5 is a sectional view showing the normal TN type liquidcrystal display device in the display area. FIG. 6 is a plan viewshowing the TFT substrate of the same liquid crystal display device. Inthis case, FIG. 5 shows a sectional shape at the position correspondingto a X-X line in FIG. 6.

[0020] The TN type liquid crystal display device consists of the TFTsubstrate 18, the CF substrate 40, and the liquid crystal 79 that issealed between the TFT substrate 18 and the CF substrate 40.

[0021] The TFT substrate 18 is constructed as described in thefollowing. That is, a plurality of gate bus lines 52 and a plurality ofstorage capacitance bus lines 53 are formed as the first wiring layer onthe glass substrate 51. Respective gate bus lines 52 are formed inparallel mutually, the storage capacitance bus lines 53 are arrangedbetween the gate bus lines 52 in parallel with the gate bus lines 52respectively.

[0022] The gate bus lines 52 and the storage capacitance bus lines 53are covered with the first insulating film (gate insulating film) (notshown). The amorphous silicon film 54 serving as the channels of theswitching TFTs 56 is formed on the first insulating film over the gatebus lines 52. Also, the data bus lines 55, and the source electrodes 56s and the drain electrodes 56 d of the TFTs 56 are formed as the secondwiring layer on the first insulating film. The data bus lines 55 areformed to intersect orthogonally with the gate bus lines 52. The sourceelectrodes 56 s and the drain electrodes 56 d of the TFTs 56 are formedon both sides of the amorphous silicon film 54 to be separated mutuallyin the width direction of the amorphous silicon film 54. Also, the drainelectrodes 56 d of the TFTs 56 are connected to the data bus lines 55.Rectangular areas that are partitioned by the gate bus lines 52 and thedata bus lines 55 act as the pixel area respectively.

[0023] The data bus lines 55, and the source electrodes 56 s and thedrain electrodes 56 d of the TFTs 56 are covered with the secondinsulating film (protection insulating film) 58. The transparent pixelelectrodes 59 made of ITO (Indium-Tin Oxide) are formed on the secondinsulating film 58. The pixel electrodes 59 are electrically connectedto the source electrodes 56 s of the TFTs 56 via the contact holes 58 aformed in the second insulating film 58 respectively.

[0024] The alignment film 57 that decides the alignment direction of theliquid crystal molecules is formed on the pixel electrodes 59. Thisalignment film 57 is formed of polyimide, for example, and the alignmentprocess is applied to the alignment film 57 by the rubbing, etc.

[0025] In contrast, the CF substrate 40 is constructed as described inthe following. That is, the black matrix 72 that is made of thelight-shielding substance such as Cr (chromium), etc. to shield theareas between respective pixels and the TFT forming areas from the lightis formed on one surface (lower surface in FIG. 5) of the glasssubstrate 71. Also, the color filter 73 having any one color of the redcolor (R), the green color (G), and the blue color (B) formed atpositions that oppose to the pixel electrodes 59 on the TFT substrate18.

[0026] The common electrode 74 made of ITO is formed under the colorfilters 73. The alignment film 75 made of polyimide, for example, isformed under the common electrode 74. The alignment process is alsoapplied to the alignment film 57 by the rubbing, etc.

[0027] Spherical or cylindrical spacers (not shown) having a uniformdiameter, for example, are arranged between the TFT substrate 18 and theCF substrate 40 such that the interval between the TFT substrate 18 andthe CF substrate 40 is constant. Also, the polarizing plate (not shown)is arranged below the TFT substrate 18 and over the CF substrate 40respectively.

[0028] In the liquid crystal display panel constructed as above, thedesired images can be displayed by supplying the scanning signals andthe video signals from the driving circuit to the gate bus lines 52 andthe data bus lines 55 at a predetermined timing to control the voltagebetween the pixel electrodes 59 and the common electrode 74 pixel bypixel.

[0029] By the way, in the liquid crystal display device, the patterningis not normally carried out because of the adhesion of dust, etc. duringthe manufacturing steps, and thus the short-circuit or the disconnectionoccurs. Therefore, the pixel is brought into the state that such pixelis normally turned ON, otherwise the pixel is brought into the statethat such pixel is normally turned OFF or such pixel as well as otherpixel is simultaneously turned ON. Normally the spot faults are allowedin the liquid crystal display device inasmuch as the number of them issmaller than a predetermined number, but the liquid crystal displaydevice becomes the defective unit if the number of faults is increased.

[0030] As the method of repairing the spot faults in the prior art, themethod of connecting the pixel electrode of the defective pixel and thegate bus lines or the storage capacitance bus lines by the laser weldinghas been known. For example, if the short-circuit occurs between thesource electrode and the drain electrode of the TFT, the pixel electrodeand the data bus line are electrically separated by cutting off thesource electrode or the drain electrode by the laser beam, and then thepixel electrode and the gate bus line or the storage capacitance busline are deposited (welded) by the laser beam. Accordingly, since thedefective pixel is brought into its normally turned OFF state, the faultof the pixel can be made inconspicuously.

[0031] However, the above fault repairing method of the liquid crystaldisplay device in the prior art can make the fault inconspicuous, butsuch method cannot repair the defective pixel to be normally driven.

[0032] In Patent Application Publication (KOKAI) Hei 2-153324, there isset forth the fault repairing method of repairing the fault in theliquid crystal display device, in which the spare TFTs are provided inaddition to the switching TFTs, by separating the switching TFT from thedata bus line if the fault occurs in the data bus line and thenconnecting the spare TFT and the pixel electrode to repair the fault.However, according to this method, since the drain electrodes of thespare TFTs are previously connected to the data bus lines via thewirings, the reduction in the display quality is brought about becauseof the large load capacitance (Cgs).

[0033] In Patent Application Publication (KOKAI) Hei 3-171034 and PatentApplication Publication (KOKAI) Hei 9-90408, the liquid crystal displaydevices in which the spare TFTs are provided in addition to theswitching TFTs are set forth. In these liquid crystal display devices,since the drain electrodes of the spare TFTs are not connected to thedata bus lines, the load capacitances are relatively small. However, inthese liquid crystal display devices, the spare wirings for connectingthe drain electrodes of the spare TFTs to the data bus lines must beprovided previously. Since the data bus lines and the drain electrodesof the spare TFTs are overlapped via these spare wirings to put theinsulating film between them, it is impossible to say that the loadcapacitance can be reduced sufficiently.

[0034] (Prior Art 4)

[0035]FIGS. 7A and 7B are schematic plan views showing the repairingmethod when the disconnection occurs in the gate bus line respectively.FIG. 7A shows the neighborhood of the connection portion of one end sideof the data bus lines and the TAB terminal, and FIG. 7B shows theneighborhood of other end side of the data bus lines.

[0036] One end side of the data bus lines 55 is connected to the TABterminal. The liquid crystal display device is connected to the TABsubstrate via these TAB terminals 60. As shown in FIGS. 7A and 7B, thefirst repair wiring 62 that intersects with a plurality of data buslines 55 are provided on one end side of the data bus lines 55. Thefirst repair wiring 62 is connected to the spare TAB terminal 61 that isaligned in parallel with the TAB terminals 60. Also, repair terminals 55a are provided to the data bus lines 55 at the intersecting portionswith the first repair wiring 62.

[0037] The second repair wiring 63, that passes through the repairterminals 55 b provided to the end portions of the data bus lines 55,and a plurality of (two in FIG. 7B) third repair wirings 64 are providedto other end side of the data bus lines 55. The top end of the secondrepair wiring 63 is bended like the L-shape, and this top end portionintersects with the third repair wirings 64. The third repair wirings 64are connected to the spare TAB terminals 65.

[0038] The above fault repairing method for the liquid crystal displaydevice will be explained with reference to FIGS. 7A and 7B and FIGS. 8Aand 8B hereunder. FIG. 8A is a sectional view taken along a XI-XI linein FIG. 7A, and FIG. 8B is a sectional view taken along a XII-XII linein FIG. 7B. It is on the assumption that the data bus lines 55 aredisconnected at positions indicated by the X mark in FIGS. 8A and 8B.Also, in FIGS. 8A and 8B, a reference 71 denotes the first insulatingfilm (gate insulating film) and a reference 72 denotes the secondinsulating film (protection insulating film).

[0039] First, as shown in FIG. 7A and FIG. 8A, the repair terminals 55 aof the data bus lines 55 and the first repair wiring 62 are welded byvirtue of the laser welding by irradiating the laser beam onto theintersecting portions of the data bus line 55, at which thedisconnection occurs, and the first repair wiring 62.

[0040] Also, as shown in FIG. 7B and FIG. 8B, the intersecting portionsof the second repair wiring 63 and the repair terminals 55 a of the databus lines 55 are electrically connected by the laser welding, and alsothe intersecting portions of the second repair wiring 63 and the thirdrepair wirings 64 are electrically connected by the laser welding.

[0041] Then, the spare TAB terminal 61 and the TAB terminals 65 areelectrically connected via the wire, etc. such that the same videosignal can be supplied to both sides of the disconnected data bus line55. As a result, it is possible to operate normally the liquid crystaldisplay device.

[0042] However, according to the method shown in FIGS. 7A and 7B andFIGS. 8A and 8B, since the first repair wiring 62 and the second repairwiring 63 intersect with the data bus lines 55, capacitances aregenerated at the intersecting portions. With the progress of the largersize and higher definition of the liquid crystal display device inrecent years, the wiring resistance of the repair wiring is increasedand also the capacitance of the intersecting portion is increased.Therefore, sometimes the signal delay is increased and the thin linefault or spot fault occurs after the fault portion is repaired. As aresult, there is the problem that the number of the repair wirings islimited.

SUMMARY OF THE INVENTION

[0043] It is an object of the present invention to provide a faultrepairing method for a liquid crystal display device for repairing adisconnection occurred in a wiring in a display area of the liquidcrystal display device.

[0044] Also, it is another object of the present invention to provide aliquid crystal display device and its fault repairing method capable ofrepairing a fault without fail if the short-circuit is generated in theportion at which an electrode, that connects storage capacitance buslines collectively, intersects with a gate bus line.

[0045] In addition, it is still another object of the present inventionto provide a fault repairing method for a liquid crystal display devicecapable of repairing a pixel in which the fault occurs to restore it toa normal pixel and reducing a load capacitance, and a liquid crystaldisplay device in which the fault can be easily repaired by its faultrepairing method.

[0046] Further, it is yet still another object of the present inventionto provide a liquid crystal display device and its fault repairingmethod capable of repairing a disconnection easily if the disconnectionoccurs in a gate bus line and a data bus line.

[0047] A fault repairing method for a liquid crystal display device setforth in claim 1 of the present invention, comprises the steps offorming first and second disconnection repairing contact holes, thathave a width larger than a width of a disconnected wiring and a depth toexpose an upper surface and both side surfaces of the disconnectedwiring respectively, at two locations which are positioned to sandwich adisconnected portion of the disconnected wiring; and forming first andsecond conductive films, that are connected electrically to the uppersurface and both side surfaces, on inner walls and surfaces of the firstand second disconnection repairing contact holes to repair thedisconnection.

[0048] According to the present invention, the disconnection repairingcontact holes which have the width larger than the width of thedisconnected wiring respectively are formed at two positions that putsthe disconnected portion of the disconnected wiring between themrespectively. Then, the disconnection can be repaired by forming theconductive films in the disconnection repairing contact holes by meansof the laser CVD method, etc. to connect electrically the disconnectionrepairing contact holes. Accordingly, the contact area between thewiring and the repairing conductive films can be extended and thereliability of connection can be increased in contrast to thedisconnection repairing method using the laser welding in the prior art.

[0049] According to the situation of the disconnection, the first andsecond conductive films can be directly connected, otherwise both thefirst and second conductive films can be connected to the pixelelectrode to be connected electrically via the pixel electrode.

[0050] Also, a fault repairing method for a liquid crystal displaydevice set forth in claim 5 of the present invention, comprises thesteps of forming a conductive film over an area located betweendisconnection end portions of a disconnected wiring by a laser CVDmethod; and connecting electrically the conductive film and thedisconnection end portions by a laser welding method to repair thedisconnection.

[0051] According to the present invention, the conductive film is formedover the disconnected portion of the disconnected wiring by the laserCVD method. Then, the disconnection can be repaired by connectingelectrically the conductive film and the end portions of thedisconnection by virtue of the laser welding method. Accordingly, thewiring in which the disconnection occurs can be easily repaired.

[0052] Also, a liquid crystal display device set forth in claim 6 of thepresent invention, in which a liquid crystal is sealed between a firstsubstrate, on which first and second wirings intersected via aninsulating film are formed, and a second substrate that opposes to thefirst substrate, comprises spare wirings that are formed in vicinity ofintersecting positions of the first and second wirings and constitute apart of a detour route used when an interlayer short-circuit between thefirst and second wirings is repaired.

[0053] Also, a liquid crystal display device set forth in claim 7 of thepresent invention, in which a liquid crystal is sealed between a firstsubstrate, on which first and second wirings intersected via aninsulating film are formed, and a second substrate that opposes to thefirst substrate, comprises spare pads that are connected to any one ofthe first and second wirings in vicinity of intersecting positions ofthe first and second wirings and constitute a part of a detour routeused when an interlayer short-circuit between the first and secondwirings is repaired.

[0054] Also, a fault repairing method for a liquid crystal displaydevice set forth in claim 8 of the present invention, comprises thesteps of disconnecting one wiring of first and second wirings in whichan interlayer short-circuit occurs, at two locations that sandwich ashort-circuit portion to separate electrically from other wiring; andforming a detour route to detouring the short-circuit portion to connectelectrically disconnection end portions of one wiring.

[0055] In the fault repairing method for the liquid crystal displaydevice according to the present invention, the detour route containsspare wirings, that are formed in vicinity of an intersecting positionof the first and second wirings to repair an interlayer short-circuitbetween the first and second wirings, as a part of its configuration.

[0056] In the fault repairing method for the liquid crystal displaydevice according to the present invention, the detour route containsspare pads, that are connected to any one of the first and secondwirings in vicinity of an intersecting position of the first and secondwirings to repair an interlayer short-circuit between the first andsecond wirings, as a part of its configuration.

[0057] According to the present invention, the short-circuit can berepaired by cutting off the wiring in which the short-circuit occurs onboth sides of the short-circuited portion respectively and then formingthe detour route to detour the short-circuited portion. At this time,the spare wiring formed previously in vicinity of the wiring, forexample, can be employed as a part of the detour route. In this manner,the wiring in which the short-circuit is caused can be repaired.

[0058] Also, a liquid crystal display device set forth in claim 11 ofthe present invention, comprises a plurality of gate bus lines; aplurality of storage capacitance bus lines; a storage capacitance busline general electrode connected commonly to the storage capacitance buslines, and arranged to intersect with the plurality of gate bus lines tosandwich an insulating film; repairing auxiliary wirings that areintersected with the storage capacitance bus line general electrode tosandwich the insulating film and are provided electrically independentlyfrom the gate bus lines; and repairing connecting electrodes arranged onboth sides of the storage capacitance bus lines in a width directionrespectively, one ends of which overlap with the gate bus lines tosandwich the insulating film between them and other ends of whichoverlap with the repairing auxiliary wirings to sandwich the insulatingfilm between them.

[0059] According to the present invention, since the repairing auxiliarywirings are provided electrically independently from the gate bus line,the identification of the short-circuited portion and the treated areacan be facilitated. Accordingly, the repairing operation can be easilycarried out and thus the fault repairing can be accomplished withoutfail.

[0060] Also, a fault repairing method for a liquid crystal displaydevice set forth in claim 16 of the present invention, that includesswitching thin film transistors that are connected to gate bus lines,data bus lines and pixel electrodes, and spare thin film transistorsthat are not connected to both the data bus lines and the pixelelectrodes, comprises the step of forming a conductive pattern, thatconnects at least a drain electrode of a spare thin film transistor anda data bus line, in repairing a fault.

[0061] Also, a fault repairing method for a liquid crystal displaydevice set forth in claim 21 of the present invention, that includesswitching thin film transistors that are connected to gate bus lines,data bus lines and pixel electrodes, and spare thin film transistorsthat are not connected to both the data bus lines and the pixelelectrodes, comprises the step of forming a conductive pattern, thatconnects at least a gate electrode of a spare thin film transistor and agate bus line, in repairing a fault.

[0062] According to the present invention, the spare thin filmtransistors are prepared previously in addition to the switching thinfilm transistors. In the spare thin film transistor, for example, a partof the gate bus line may be formed as the gate electrode, or the gateelectrode may be formed between the pixel electrode and the data busline. In the situation before the fault repairing is carried out, thespare thin film transistor is neither connected to the pixel electrodenor any one of the gate bus line and the data bus line. Accordingly, theincrease in the load capacitance can be avoided and also the reductionin the display quality can be prevented.

[0063] Furthermore, according to the present invention, in repairing thedefective pixel, the conductive pattern for connecting the drainelectrode of the spare thin film transistor and the data bus line or theconductive pattern for connecting the gate electrode of the spare thinfilm transistor and the gate bus line is formed. This conductive patternis formed by depositing the metal film by means of the laser CVD methodor by laser-baking the conductive chemicals (conductive paste), forexample. According to this method, the conductive pattern can be formedon the insulating film or the conductive film with good adhesiveness.Also, the source electrode of the spare thin film transistor isconnected to the pixel electrode by the melt-joint using the laser, forexample. According to the present invention, since the pixel can bedriven by the spare thin film transistor by connecting the spare thinfilm transistor, the pixel electrode, the gate bus line, and the databus line in this manner, the high quality image display without faultcan be achieved.

[0064] Also, a fault repairing method for a liquid crystal displaydevice set forth in claim 28 of the present invention, that includes aplurality of bus lines formed on a substrate, TAB terminals arrangedalong a first side of the substrate and connected to the bus linesrespectively, and repair wirings arranged along a second side opposingto the first side, comprises the step of forming at least a conductivepattern for connecting electrically a bus line and a repair wiring, inrepairing the fault.

[0065] According to the present invention, when the disconnection occursin the bus line, the conductive pattern for connecting the end portionof the disconnection opposite to the TAB terminal of the bus line andthe repair wiring is formed. That is, since the repair wiring does notoverlap with the bus line before the fault repairing is carried out, theload capacitance is small and thus the signal delay can be prevented. Asa result, the degradation of the display quality due to the repairwiring can be avoided.

[0066] According to the present invention, the conductive pattern can beformed by the laser CVD method or by baking the conductive chemicals(conductive paste), for example. The conductive pattern can be formed onthe insulating film with good adhesiveness by using these methods.

BRIEF DESCRIPTION OF THE DRAWINGS

[0067]FIG. 1 is a top view showing a configuration of a liquid crystaldisplay device;

[0068]FIG. 2 is a view (#1) showing a configuration of the liquidcrystal display device in the prior art, i.e., an enlarged view showinga portion encircled by a broken line in FIG. 1;

[0069]FIG. 3 is a view (#2) showing a configuration of the liquidcrystal display device in the prior art, i.e., a view showing an exampleof an intersecting portion of a storage capacitance bus line generalelectrode and a gate bus line;

[0070]FIG. 4 is a view (#3) showing a configuration of the liquidcrystal display device in the prior art, i.e., a view showing anotherexample of the intersecting portion of the storage capacitance bus linegeneral electrode and the gate bus line;

[0071]FIG. 5 is a sectional view showing a configuration of a normal TNtype liquid crystal display device in the prior art;

[0072]FIG. 6 is a plan view showing a TFT substrate of the same liquidcrystal display device in the prior art;

[0073]FIGS. 7A and 7B are schematic plan views showing a method ofrepairing disconnection of a gate bus line in the prior artrespectively;

[0074]FIGS. 8A and 8B are sectional views showing the method ofrepairing the disconnection of the gate bus line in the prior artrespectively;

[0075]FIG. 9 is a plan view showing a schematic configuration of adisplay panel of a liquid crystal display device serving as a premise ofa liquid crystal display device and its fault repairing method accordingto a first embodiment of the present invention;

[0076]FIGS. 10A and 10B, FIGS. 11A and 11B, FIGS. 12A and 12B, FIGS. 13Aand 13B, FIGS. 14A and 14B, and FIGS. 15A and 15B are schematicsectional views showing a method of manufacturing the display panel ofthe same liquid crystal display device respectively;

[0077]FIG. 16 is a plan view showing an outline of an example 1 of afault repairing method for a liquid crystal display device according toa first embodiment of the present invention;

[0078]FIGS. 17A to 17D are sectional views showing the example 1 of thefault repairing method according to the first embodiment of the presentinvention;

[0079]FIG. 18 is a plan view showing an outline of an example 2 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0080]FIGS. 19A to 19D are sectional views showing the example 2 of thefault repairing method according to the first embodiment of the presentinvention;

[0081]FIG. 20 is a plan view showing an outline of an example 3 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0082]FIG. 21 is a plan view showing an outline of an example 4 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0083]FIGS. 22A to 22D are sectional views showing the example 4 of thefault repairing method according to the first embodiment of the presentinvention;

[0084]FIG. 23 is a plan view showing an outline of an example 5 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0085]FIGS. 24A to 24C are sectional views showing the example 5 of thefault repairing method according to the first embodiment of the presentinvention;

[0086]FIG. 25 is a plan view showing an outline of an example 6 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0087]FIG. 26 is a plan view showing an outline of an example 7 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0088]FIGS. 27A to 27D are sectional views showing the example 7 of thefault repairing method according to the first embodiment of the presentinvention;

[0089]FIG. 28 is a plan view showing an outline of an example 8 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0090]FIG. 29 is a plan view showing an outline of an example 9 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0091]FIGS. 30A to 30C are sectional views showing the example 9 of thefault repairing method according to the first embodiment of the presentinvention;

[0092]FIG. 31 is a plan view showing an outline of an example 10 of afault repairing method for a liquid crystal display device according tothe first embodiment of the present invention;

[0093]FIGS. 32A and 32B, FIGS. 33A and 33B, and FIGS. 34A and 34B aresectional views showing the example 10 of the fault repairing methodaccording to the first embodiment of the present invention;

[0094]FIGS. 35A to 35D are views showing the principle of a liquidcrystal display device and a fault repairing method according to asecond embodiment of the present invention;

[0095]FIG. 36 is a plan view showing an outline of an example 1 of theliquid crystal display device and its fault repairing method accordingto the second embodiment of the present invention;

[0096]FIG. 37 is a schematic sectional view (#1) showing the example 1of the fault repairing method according to the second embodiment of thepresent invention;

[0097]FIG. 38 is a schematic sectional view (#2) showing the example 1of the fault repairing method according to the second embodiment of thepresent invention;

[0098]FIG. 39 is a plan view showing an outline of an example 2 of theliquid crystal display device and its fault repairing method accordingto the second embodiment of the present invention;

[0099]FIG. 40 is a schematic sectional view (#1) showing the example 2of the fault repairing method according to the second embodiment of thepresent invention;

[0100]FIG. 41 is a schematic sectional view (#2) showing the example 2of the fault repairing method according to the second embodiment of thepresent invention;

[0101]FIG. 42 is a plan view showing an outline of an example 3 of theliquid crystal display device and its fault repairing method accordingto the second embodiment of the present invention;

[0102]FIG. 43 is a schematic sectional view (#1) showing the example 3of the fault repairing method according to the second embodiment of thepresent invention;

[0103]FIG. 44 is a schematic sectional view (#2) showing the example 3of the fault repairing method according to the second embodiment of thepresent invention;

[0104]FIG. 45 is a plan view showing an outline of an example 4 of theliquid crystal display device and its fault repairing method accordingto the second embodiment of the present invention;

[0105]FIG. 46 is a schematic sectional view (#1) showing the example 4of the fault repairing method according to the second embodiment of thepresent invention;

[0106]FIG. 47 is a schematic sectional view (#2) showing the example 4of the fault repairing method according to the second embodiment of thepresent invention;

[0107]FIG. 48 is a plan view showing an outline of an example 5 of theliquid crystal display device and its fault repairing method accordingto the second embodiment of the present invention;

[0108]FIG. 49 is a schematic sectional view showing the example 5 of thefault repairing method according to the second embodiment of the presentinvention;

[0109]FIG. 50 is a plan view showing an outline of an example 6 of theliquid crystal display device and its fault repairing method accordingto the second embodiment of the present invention;

[0110]FIG. 51 is a schematic sectional view (#1) showing the example 6of the fault repairing method according to the second embodiment of thepresent invention;

[0111]FIG. 52 is a schematic sectional view (#2) showing the example 6of the fault repairing method according to the second embodiment of thepresent invention;

[0112]FIG. 53 is a schematic sectional view (#3) showing the example 6of the fault repairing method according to the second embodiment of thepresent invention;

[0113]FIG. 54 is a view (#1) showing the principle of the invention usedin a third embodiment of the present invention;

[0114]FIG. 55 is a view (#2) showing the principle of the invention usedin the third embodiment of the present invention, i.e., a view showing ashort-circuit repairing method;

[0115]FIG. 56 is a view (#3) showing the principle of the invention usedin the third embodiment of the present invention, i.e., a sectional viewtaken along a I-I line in FIG. 55;

[0116]FIG. 57 is a view showing a short-circuit repairing methodaccording to a third embodiment of the present invention;

[0117]FIG. 58 is a view showing a part of FIG. 57 in an enlarged manner;

[0118]FIG. 59 is a sectional view taken along a II-II line in FIG. 58;

[0119]FIG. 60 is a plan view showing a TFT substrate of a liquid crystaldisplay device according to a fourth embodiment of the presentinvention;

[0120]FIG. 61 is a plan view showing a fault repairing method for theliquid crystal display device according to the fourth embodiment of thepresent invention;

[0121]FIGS. 62A to 62C are schematic sectional views showing the faultrepairing method for the liquid crystal display device according to thefourth embodiment of the present invention;

[0122]FIGS. 63A to 63C are schematic sectional views showing a faultrepairing method for a liquid crystal display device according to afifth embodiment of the present invention;

[0123]FIG. 64 is a plan view showing a TFT substrate of a liquid crystaldisplay device according to a sixth embodiment of the present invention;

[0124]FIG. 65 is a plan view showing a fault repairing method for theliquid crystal display device according to the sixth embodiment of thepresent invention;

[0125]FIG. 66 is a plan view showing a TFT substrate of a liquid crystaldisplay device according to a seventh embodiment of the presentinvention;

[0126]FIG. 67 is a plan view showing a fault repairing method for theliquid crystal display device according to the seventh embodiment of thepresent invention;

[0127]FIG. 68 is a sectional view taken along a III-III line in FIG. 67;

[0128]FIG. 69 is a schematic view showing a TFT substrate of a liquidcrystal display device according to an eighth embodiment of the presentinvention;

[0129]FIGS. 70A and 70B are schematic views showing an example of afault repairing method according to the eighth embodiment of the presentinvention;

[0130]FIGS. 71A and 71B are sectional views taken along a IV-IV line anda V-V line in FIG. 70A and 70B respectively;

[0131]FIGS. 72A and 72B are views showing another example of the faultrepairing method according to the eighth embodiment of the presentinvention, i.e., views showing an example in which repair terminals andrepair wirings are arranged on the outside of a CF substrate;

[0132]FIGS. 73A and 73B are schematic views showing a fault repairingmethod according to a ninth embodiment of the present invention; and

[0133]FIGS. 74A and 74B are sectional views taken along a VI-VI line anda VII-VII line in FIGS. 73A and 73B respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0134] Embodiments of the present invention will be explained in detailwith reference to the accompanying drawings hereinafter.

[0135] (First Embodiment)

[0136] A fault repairing method for a liquid crystal display deviceaccording to a first embodiment of the present invention will beexplained with reference to FIG. 9 to FIG. 34B hereunder. FIG. 9 is aplan view showing a schematic configuration of a display panel of aliquid crystal display device serving as a premise of a liquid crystaldisplay device and its fault repairing method according to the firstembodiment of the present invention. FIG. 9 shows the substrate sidewhen a TFT substrate of a liquid crystal display panel is viewed fromthe liquid crystal layer side.

[0137] As shown in FIG. 9, a plurality of data bus lines 101 extended inthe longitudinal direction in FIG. 9 are formed on the substrate. Also,a plurality of gate bus lines 103 indicated by a broken line extended inthe lateral direction in FIG. 9 are formed on the substrate. Respectiveareas that are defined by the data bus lines 101 and the gate bus lines103 are pixel areas. Then, TFTs are formed in vicinity of theintersection position of the data bus lines 101 and the gate bus lines103.

[0138] A drain electrode 117 of the TFT is extracted from the left sidedata bus line 101, and is formed such that one end portion of the drainelectrode 117 is positioned at one end side on a channel protection film105 formed on the gate bus line 103.

[0139] Meanwhile, a source electrode 119 is formed such that it ispositioned at other end side on the channel protection film 105. In suchconfiguration, the portion of the gate bus line 103 positionedimmediately under the channel protection film 105 functions as the gateelectrode of the TFT. Although not shown, the gate insulating film isformed on the gate bus line 103 and then a semiconductor filmconstituting the channel is formed thereon.

[0140] Also, a storage capacitance bus line 115 is formed in the areaindicated by a broken line extended laterally in the almost middle ofthe pixel area. A storage capacitance electrode 109 is formed over thestorage capacitance bus line 115 via an insulating film every pixel. Thesource electrode 119 and the storage capacitance electrode 109 arecovered with an insulating protection film. A pixel electrode 113 madeof a transparent electrode is formed on the insulating protection film.

[0141] The pixel electrode 113 is connected electrically to the sourceelectrode 119 via a contact hole 107 provided in the insulatingprotection film. Also, the pixel electrode 113 is connected electricallyto the storage capacitance electrode 109 via a contact hole 111.

[0142] Next, a method of manufacturing the liquid crystal display deviceshown in FIG. 9 will be explained with reference to FIGS. 10A and 10B,FIGS. 11A and 11B, FIGS. 12A and 12B, FIGS. 13A and 13B, FIGS. 14A and14B, and FIGS. 15A and 15B hereunder. In FIG. 10A to FIG. 15B, the samesymbols are affixed to the same constituent elements as those shown inFIG. 9. Also, FIG. 10A, FIG. 11A, FIG. 12A, FIG. 13A, FIG. 14A, and FIG.15A show a sectional shape of the TFT taken along an M-M′ line in FIG. 9respectively, and FIG. 10B, FIG. 11B, FIG. 12B, FIG. 13B, FIG. 14B, andFIG. 15B show a sectional shape of the storage capacitor portion takenalong an N-N′ line in FIG. 9 respectively.

[0143] First, as shown in FIGS. 10A and 10B, a metal film of about 150nm thickness is formed on a transparent glass substrate 121 by formingAl (aluminum), for example, on the overall surface. Then, the gate busline 103 (see FIG. 10A) and the storage capacitance bus line 115 (seeFIG. 10B) are formed by patterning this metal film by using a firstmask. Then, a gate insulating film 123 of about 40 nm thickness isformed by forming a silicon nitride (SiN) film, for example, on theoverall surface of the substrate by virtue of the plasma CVD method.Then, an amorphous silicon (a-Si) film 125 serving as the channel of theTFT is formed on the overall surface of the substrate by the plasma CVDmethod to have a thickness of about 15 μm, for example. Then, a siliconnitride (SiN) film 127 serving as the channel protection film is formedon the overall surface by the plasma CVD method to have a thickness ofabout 120 nm, for example.

[0144] Then, a photoresist film is coated on the overall surface, thenthe back exposure is applied to the transparent glass substrate 121while using the gate bus line 103 and the storage capacitance bus line115 as a mask, and then the exposure using a second mask is carried out.Then, a resist pattern (not shown) is formed in a self-alignment manneron the gate bus line 103 by the developing process. Then, the channelprotection film 105 is formed on the gate bus line 103 in the TFTforming region by etching the silicon nitride film 127 while using thisresist pattern as a mask (see FIGS. 11A and 11B).

[0145] Then, as shown in FIGS. 12A and 12B, an n⁺ a-Si film 129 servingas an ohmic contact layer is formed on the overall surface by the plasmaCVD method to have a thickness of about 30 nm, for example. Then, ametal layer (e.g., a Cr layer) 131 serving as the drain electrode 117,the source electrode 119, the storage capacitance electrode 109, and thedata bus line 101 is formed by the sputtering to have a thickness ofabout 170 nm, for example.

[0146] Then, as shown in FIGS. 13A and 13B, the data bus line 101 (notshown in FIGS. 13A and 13B), the drain electrode 117, the sourceelectrode 119, the storage capacitance electrode 109, and thesemiconductor film 106 are formed by etching the metal film 131, the n⁺a-Si film 129, and the amorphous silicon film 125 while using a thirdmask. In this etching process, the channel protection film 105 canfunction as the etching stopper and thus the underlying amorphoussilicon film 125 is not etched to remain.

[0147] Then, as shown in FIGS. 14A and 14B, a protection insulating film133 made of a silicon nitride film, for example, is formed by the plasmaCVD method to have a thickness of about 30 nm. Then, the protectioninsulating film 133 is patterned while using a fourth mask to form thecontact hole 107 on the source electrode 119 and also form the contacthole 111 on the storage capacitance electrode 109.

[0148] Then, as shown in FIGS. 15A and 15B, a transparent pixelelectrode material 135 made of ITO and having a thickness of about 70nm, for example, is formed on the overall upper surface of thetransparent glass substrate 121. Then, a pixel electrode 113 having apredetermined profile, as shown in FIG. 9, is formed by patterning thepixel electrode material 135 using as a fifth mask. The pixel electrode113 is connected electrically to the source electrode 119 via thecontact hole 107, and also is connected electrically to the storagecapacitance electrode 109 via the contact hole 111.

[0149] The display panel of the liquid crystal display device shown inFIG. 9 can be completed via the steps described above. If thedisconnection occurs in the wiring patterns such as the gate bus line103, the data bus line 101, the storage capacitance bus line 115, etc.in the middle of above steps, the display panel can be restored to thenon-defective unit by carrying out the fault repairing method accordingto embodiments shown in (A) to (G) described in the following.

[0150] (A) Two hole patterns are formed by coating the resist on theoverall surface of the substrate, and then applying the spot-exposure orthe laser beam irradiation to the resist film on two wiring patterns onboth sides of the disconnected portion to pattern (develop) the resistfilm. The hole patterns are formed to have a length longer than a linewidth of the wiring pattern and to extend across the width of the wiringpattern.

[0151] (B) Then, two disconnection repairing contact holes are formed bydry-etching the insulating film (the protection insulating film 133 orthe protection insulating film 133 and the insulating film 123) whileusing the resist film as a mask to expose the upper surface and sidesurfaces of the wiring pattern.

[0152] (C) The disconnection repairing contact holes are filled with alaser CVD film made of organic metal compound by virtue of the laser CVD(Chemical Vapor Deposition) method using the laser beam.

[0153] (D) The laser CVD films that are filled in the disconnectionrepairing contact holes are connected via the laser CVD film. Otherwise,(E) respective laser CVD films that are filled in two disconnectionrepairing contact holes are connected to the same pixel electrode byusing the laser CVD method. Otherwise, (F) the laser CVD films that arefilled in two disconnection repairing contact holes are connected todifferent pixel electrodes via the laser CVD film respectively, and thenthe pixel electrodes are connected via the laser CVD film. At this time,the connection between the drain electrode of the TFT connected to oneor both of the pixel electrodes and the data bus line should bedisconnected.

[0154] Alternatively, (G) the disconnection repairing contact holes arenot provided, but the laser CVD film that is wider than the disconnectedwiring pattern is formed on the protection film at the disconnectionportion to cross the disconnection portion. Then, the laser CVD film andboth end portions of the disconnected wiring pattern are connected onboth end sides of the disconnection portion by the laser welding method.

[0155] According to the disconnection fault repairing method of thefirst embodiment, at least five advantages described in the followingcan be achieved. First, since the disconnection repairing contact holesare formed by dry-etching the insulating film prior to the formation ofthe pixel electrode, such disconnection repairing contact holes can beformed with good precision, without the contamination of the pixelelectrode caused by the laser beam irradiation, unlike the prior art.Second, since the disconnection repairing contact holes are formed toexpose the side surfaces of the wiring pattern also, the contact areacan be spread and the reliability of connection can be enhanced ratherthan the case where the contact holes are formed only on the wiringpattern.

[0156] Third, since the disconnection repairing contact holes are formedmerely at one location on both sides of the disconnection portionrespectively, such contact holes can be filled simply with the laser CVDfilm without fail rather than the case where a plurality of contactholes are provided. Fourth, since the detour connection can beaccomplished by using the laser CVD film via the pixel electrode, thelong disconnection portion can be repaired. Thus, most of thedisconnection faults or the interlayer short-circuit faults can berelieved.

[0157] Fifth, since the laser CVD films can be locally formed on theinsulating film at the disconnection portion and then they can beconnected from the back surface or the front surface by the laserwelding, such laser CVD films can be connected simply not to increasethe number of masks. In this case, since there is no necessity to formthe disconnection repairing contact holes, the repairing operation canbe performed in the middle of the steps as occasion demands.

[0158] Then, the fault repairing method according to the firstembodiment will be explained with reference to particular exampleshereunder.

EXAMPLE 1

[0159]FIG. 16 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. In FIG. 16, the same symbols are affixed to the sameconstituent elements as those shown in FIG. 9. FIG. 16 shows such asituation that the data bus line 101 located on the left side in FIG. 16is disconnected at a disconnected portion 201 between the gate bus line103 located on the upper side in FIG. 16 and the storage capacitance busline 115.

[0160] First, disconnection repairing contact holes 203, 205 whosewidths are larger than the width of the data bus line 101 are formed ondisconnection end portions of the data bus line 101 on both ends of thedisconnected portion 201 respectively to cross the data bus line 101.The data bus line 101 containing its side surfaces is exposed from thedisconnection repairing contact holes 203, 205. Then, the data bus line101 in the disconnection repairing contact holes 203, 205 and the pixelelectrode 113 are connected by laser CVD films 209, 211 respectively.Also, the drain electrode 117 of the TFT of the pixel that is located inthe neighborhood of the disconnected portion 201 is separated from thedata bus line 101 by irradiating the laser beam to a cutting position213 at the root portion of the drain electrode 117. In this manner, thedisconnection fault occurred in the data bus line (drain bus line) 101can be repaired surely.

[0161] The disconnection repairing method in the example 1 will beexplained in more detail with reference to FIGS. 17A to 17D hereunder.FIGS. 17A to 17D show a sectional shape in vicinity of the data bus line101 taken along a P-P′ line in FIG. 16 respectively. In this case, thesame symbols are affixed to the same constituent elements as those shownin FIG. 10A to FIG. 15B. Similarly, the same symbols are affixed to thesame constituent elements as those in the accompanying drawings in thefollowing explanation.

[0162] It is on the assumtion that the disconnection inspection of thegate bus lines 103 and the data bus lines 101 has been carried outbefore the contact holes 107, 111 shown in FIG. 16 are formed, and thatthe disconnected portion 201 of the data bus line 101 shown in FIG. 16is found as the result of the disconnection inspection.

[0163] In order to form the contact holes 107 and 111, a resist film 215is formed by coating the photoresist on the overall surface of thesubstrate. Then, as shown in FIG. 17A, a hole 217 that has a widthlarger than the width of the data bus line 101 is formed by applying thespot-exposure or the laser beam irradiation (e.g., excimer laser beamirradiation) to the resist film 215 on the disconnection end portions ofthe data bus line 101 on both sides of the disconnected portion 201 andthen patterning (developing) the resist film 215.

[0164] Then, as shown in FIG. 17B, the formation of the contact holes107, 111 and the window opening of the terminal portion (not shown) arecarried out by the selective etching using the dry etching. At the sametime, by selectively etching the inside of the hole 217, an uppersurface of the disconnection end portion of the data bus line 101 isexposed, and also the disconnection repairing contact hole 205 reachingthe surface of the glass substrate 121 is formed on both sides of thedata bus line 101 in the width direction. Similarly, the disconnectionrepairing contact hole 203 is also formed.

[0165] Then, as shown in FIG. 17C, the pixel electrode 113 is formed byforming the film of the transparent electrode material such as ITO, etc.on the overall surface of the substrate and then patterning the film.

[0166] Then, as shown in FIG. 17D, a laser CVD film 211 for connectingthe inside of the disconnection repairing contact hole 205 and the pixelelectrode 113 is formed by the laser CVD method. Similarly, a laser CVDfilm 209 for connecting the inside of the disconnection repairingcontact hole 203 and the pixel electrode 113 is formed by the laser CVDmethod.

[0167] In this manner, as shown in FIG. 16, one disconnection endportion and the other disconnection end portion of the data bus line 101are connected electrically by the laser CVD film 209, that is formedbetween the disconnection repairing contact hole 203 and the pixelelectrode 113, and the laser CVD film 211, that is formed between thedisconnection repairing contact hole 205 and the pixel electrode 113.Thus, the disconnection fault can be repaired.

[0168] According to this example 1, since the disconnection repairingcontact holes are formed by dry-etching the insulating film prior to theformation of the pixel electrode, such disconnection repairing contactholes can be formed with good precision, without the contamination ofthe pixel electrode caused by the laser beam irradiation, unlike theprior art. Also, the repairing operation can be carried out not toincrease the number of masks.

[0169] In addition, since the disconnection repairing contact holes areformed to have the width larger than the data bus line, the contact areacan be spread and the reliability of connection can be enhanced ratherthan the case where the contact holes are formed only on the data busline.

[0170] Further, since the disconnection repairing contact holes areformed merely at one location on both sides of the disconnection portionrespectively, such contact holes can be filled simply with the laser CVDfilm without fail rather than the case where a plurality of contactholes are provided.

[0171] Moreover, since the detour connection can be accomplished byusing the laser CVD film via the pixel electrode, the long disconnectionportion can be repaired. Thus, most of the disconnection faults or theinterlayer short-circuit faults can be relieved.

EXAMPLE 2

[0172]FIG. 18 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. FIG. 18 shows such a situation that, like the example1, the data bus line 101 located on the left side in FIG. 18 isdisconnected at a disconnected portion 231 between the gate bus line 103located on the upper side in FIG. 18 and the storage capacitance busline 115.

[0173] First, disconnection repairing contact holes 233, 235 whosewidths are larger than the width of the data bus line 101 are formed ondisconnection end portions of the data bus line 101 on both ends of thedisconnected portion 201 respectively to cross the data bus line 101.Then, the disconnection end portions of the data bus line 101 in thedisconnection repairing contact holes 233, 235 are connected by a laserCVD film 237. In this manner, the disconnection fault occurred in thedata bus line 101 can be repaired firmly.

[0174] The disconnection repairing method in the example 2 will beexplained in more detail with reference to FIGS. 19A to 19D hereunder.FIGS. 19A to 19D show a sectional shape in vicinity of the data bus line101 taken along a Q-Q′ line in FIG. 18 respectively. It is on theassumption that the disconnection inspection of the gate bus lines 103and the data bus lines 101 has been carried out before the contact holes107, 111 shown in FIG. 18 are formed, and that the disconnected portion231 of the data bus line 101 shown in FIG. 18 is found as the result ofthe disconnection inspection.

[0175] In order to form the contact holes 107 and 111, a resist film 239is formed by coating the photoresist on the overall surface of thesubstrate. Then, as shown in FIG. 19A, holes 241, 243 that have a widthlarger than the width of the data bus line 101 respectively are formedby applying the spot-exposure or the laser beam irradiation to theresist film 239 on the disconnection end portions of the data bus line101 on both sides of the disconnected portion 231 and then patterningthe resist film 239.

[0176] Then, as shown in FIG. 19B, the formation of the contact holes107, 111 and the window opening of the terminal portion (not shown) arecarried out by the selective etching using the dry etching. At the sametime, by selectively etching the inside of the holes 241, 243, the uppersurface of the disconnection end portion of the data bus line 101 isexposed, and also disconnection repairing contact holes 247, 249reaching the surface of the glass substrate 121 are formed on both sidesof the data bus line 101 in the width direction.

[0177] Then, as shown in FIG. 19C, a laser CVD film 250 for connectingthe insides of the disconnection repairing contact holes 247, 249 andthe data bus line 101 is formed by the laser CVD method. Then, as shownin FIG. 19D, the pixel electrode 113 is formed by forming the film ofthe transparent electrode material such as ITO, etc. on the overallsurface of the substrate and then patterning the film.

[0178] In this manner, as shown in FIG. 18, one disconnection endportion and the other disconnection end portion of the data bus line 101are connected electrically by the laser CVD film 237 that is formedbetween the disconnection repairing contact holes 233, 235. Thus, thedisconnection fault can be repaired.

[0179] According to this example 2, since the disconnection repairingcontact holes are formed by dry-etching the insulating film prior to theformation of the pixel electrode, such disconnection repairing contactholes can be formed with good precision, without the contamination ofthe pixel electrode caused by the laser beam irradiation, unlike theprior art. Also, the repairing operation can be carried out not toincrease the number of masks.

[0180] In addition, since the disconnection repairing contact holes areformed to have the width larger than the data bus line, the contact areacan be spread and the reliability of connection can be enhanced ratherthan the case where the contact holes are formed only on the data busline.

[0181] In this case, the connection of the wirings by the laser CVDmethod may be carried out after the pixel electrode has been formed.

EXAMPLE 3

[0182]FIG. 20 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. FIG. 20 shows pixel electrodes 113 a, 113 b, 113 c,113 d in four pixel areas that are defined by three data bus lines 101a, 101 b, 101 c and three gate bus lines 103 a, 103 b, 103 c. A storagecapacitance bus line 115 a or 115 b is formed in each pixel area.

[0183]FIG. 20 shows such a situation that the data bus line 101 b isdisconnected at a disconnected portion 251 that extends over two pixelareas to cross the gate bus line 103 b, and thus the connection betweenthe drain electrode 117 d of the TFT connected to the pixel electrode113 d and the data bus line 101 b is cut off.

[0184] In this Example 3, first, disconnection repairing contact holes253, 255 whose width is larger than the width of the data bus line 101 bare formed on disconnection end portions of the data bus line 101 blocated on both sides of the disconnected portion 251 respectively, likethe example 1. Then, the laser CVD film 257 that connects the data busline 101 b in the disconnection repairing contact hole 253 and the leftside end of the pixel electrode 113 b is formed, and similarly the laserCVD film 259 that connects the data bus line 101 b in the disconnectionrepairing contact hole 255 and the left side end of the pixel electrode113 d is formed. Also, the laser CVD film 261 that directly connects thelower side end of the pixel electrode 113 b and the upper side end ofthe pixel electrode 113 d. In this case, prior to the formation of thepixel electrodes 113 a to 113 d, the drain electrode 117 b of the TFTconnected to the pixel electrode 113 b is separated from the data busline 101 b by irradiating the laser beam to a cutting position 263 atthe root portion of the drain electrode 117 b so as to cut off theconnection to the data bus line 101 b.

[0185] As a result, one disconnection end portion of the data bus line101 b is connected to the pixel electrode 113 b via the laser CVD film257 in the disconnection repairing contact hole 253, and the otherdisconnection end portion of the data bus line 101 b is connected to thepixel electrode 113 d via the laser CVD film 259 in the disconnectionrepairing contact hole 255, and the pixel electrode 113 b and the pixelelectrode 113 d are connected by the laser CVD film 261. Therefore, theelectrical connection can be routed to detour the disconnected portion251 of the data bus line 101 b. In addition, since the disconnectionrepairing contact holes 253, 255 are formed in the same way as theexamples 1, 2, the electrical connection with the high reliability canbe obtained similarly.

EXAMPLE 4

[0186]FIG. 21 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. In FIG. 21, three data bus lines 101 a, 101 b, 101 cand two gate bus lines 103 a, 103 b are shown, and two pixel areas(pixel electrodes 113 a, 113 b) defined by these bus lines are shown.Also, the storage capacitance bus line 115 to traverse two pixel areasis shown.

[0187] In addition, in FIG. 21, the gate bus line 103 a is disconnected(disconnected portion 271) between the channel protection film 105 a ofthe TFT, that is connected to the data bus line 111 a, and the data busline 101 b.

[0188] First, disconnection repairing contact holes 273, 275 whose widthis larger than the width of the gate bus line 103 a are formed on thegate bus line 103 a in vicinity of corner portions of the pixelelectrode 113 a respectively. Then, the laser CVD films 277, 279 thatconnects the gate bus line 103 a in the disconnection repairing contactholes 273, 275 and the pixel electrode 113 a are formed. In this case,the drain electrode 117 a of the TFT connected to the pixel electrode113 a is separated from the data bus line 101 a by irradiating the laserbeam to a cutting position 281 at the root portion of the drainelectrode 117 a so as to cut off the connection to the data bus line 101a.

[0189] The disconnection repairing method in the example 4 will beexplained in more detail with reference to FIGS. 22A to 22D hereunder.FIGS. 22A to 22D show a sectional shape in vicinity of the gate bus line103 a taken along an S-S′ line in FIG. 21 respectively. It is on theassumption that the disconnection inspection of the gate bus lines 103and the data bus lines 101 has been carried out before the contact holes107, 111 shown in FIG. 21 are formed, and that the disconnected portion271 of the gate bus line 103 a shown in FIG. 21 is found as the resultof the disconnection inspection.

[0190] In order to form the contact holes 107 and 111, a resist film 283is formed by coating the photoresist on the overall surface of thesubstrate. Then, as shown in FIG. 22A, a resist hole 285 that has awidth larger than the width of the gate bus line 103 a is formed byapplying the spot-exposure or the laser beam irradiation to the resistfilm 283 on the disconnection end portions of the gate bus line 103 a onboth sides of the disconnected portion 271 (see FIG. 21) and thenpatterning (developing) the resist film 283.

[0191] Then, as shown in FIG. 22B, the formation of the contact holes107, 111 and the window opening of the terminal portion (not shown) arecarried out by the selective etching using the dry etching. At the sametime, by selectively etching the inside of the hole 285, an uppersurface of the disconnection end portion of the gate bus line 103 a isexposed, and also the disconnection repairing contact hole 287 reachingthe surface of the glass substrate 121 is formed on both sides of thegate bus line 103 a in the width direction.

[0192] Then, as shown in FIG. 22C, the pixel electrode 113 is formed byforming the film of the transparent electrode material such as ITO, etc.on the overall surface of the substrate and then patterning the film.Then, as shown in FIG. 22D, a laser CVD film 279 for connecting the gatebus line 103 a in the disconnection repairing contact hole 287 and thepixel electrode 113 a is formed by the laser CVD method. Similarly, alaser CVD film 277 for connecting the gate bus line 103 a in thedisconnection repairing contact hole 273 and the pixel electrode 113 ais formed by the laser CVD method.

[0193] In this manner, as shown in FIG. 21, one disconnection endportion and the other disconnection end portion of the gate bus line 103a are connected electrically by the laser CVD film 277, that is formedbetween the disconnection repairing contact hole 273 and the pixelelectrode 113 a, and the laser CVD film 279, that is formed between thedisconnection repairing contact hole 275 and the pixel electrode 113 a.Thus, the disconnection fault can be repaired.

[0194] According to this example 4, since the disconnection repairingcontact holes are formed by dry-etching the insulating film before theformation of the pixel electrode, such disconnection repairing contactholes can be formed with good precision, without the contamination ofthe pixel electrode caused by the laser beam irradiation, unlike theprior art. Also, the repairing operation can be carried out not toincrease the number of masks.

[0195] In addition, since the disconnection repairing contact holes areformed to have the width larger than the data bus line, the contact areacan be spread and the reliability of connection can be enhanced ratherthan the case where the contact holes are formed only on the data busline.

[0196] Further, since the disconnection repairing contact holes areformed merely at one location on both sides of the disconnection portionrespectively, such contact holes can be filled simply with the laser CVDfilm without fail rather than the case where a plurality of contactholes are provided.

[0197] Moreover, since the detour connection can be accomplished byusing the laser CVD film via the pixel electrode, the long disconnectionportion can be repaired. Thus, most of the disconnection faults can berelieved.

EXAMPLE 5

[0198]FIG. 23 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. In FIG. 23, three data bus lines 101 a, 101 b, 101 cand two gate bus lines 103 a, 103 b are shown, and also two pixel areas(pixel electrodes 113 a, 113 b) defined by these bus lines are shown.Also, the storage capacitance bus line 115 to traverse two pixel areasis shown.

[0199] In FIG. 23, the gate bus line 103 a is disconnected at adisconnected portion 301 between the channel protection film 105 a ofthe TFT, that is connected to the data bus line 101 a, and the data busline 101 b.

[0200] First, disconnection repairing contact holes 303, 305 whose widthis larger than the width of the gate bus line 103 a are formed on thedisconnected end portions of the gate bus line 103 a on both ends of thedisconnected portion 301 respectively. The gate bus line 103 acontaining its side surfaces are exposed in the disconnection repairingcontact holes 303, 305. Then, a laser CVD film 307 that connects thegate bus line 103 a in the disconnection repairing contact holes 303,305 is formed. In this manner, the disconnection fault occurred in thegate bus line can be repaired without fail.

[0201] The disconnection repairing method in the example 5 will beexplained in more detail with reference to FIGS. 24A to 24C hereunder.FIGS. 24A to 24C show a sectional shape in vicinity of the gate bus line103 a taken along a T-T′ line in FIG. 23 respectively. It is on theassumption that the disconnection inspection of the gate bus lines 103and the data bus lines 101 has been carried out before the contact holes107, 111 shown in FIG. 23 are formed, and that the disconnected portion301 of the gate bus line 103 a shown in FIG. 23 is found as the resultof the disconnection inspection.

[0202] In order to form the contact holes 107 and 111, a resist film 309is formed by coating the photoresist on the overall surface of thesubstrate. Then, as shown in FIG. 24A, holes 311, 313 that have a widthlarger than the width of the gate bus line 103 a to transverse the gatebus line 103 a are formed by applying the spot-exposure or the laserbeam irradiation to the resist film 309 located at the disconnection endportions of the gate bus line 103 a on both sides of the disconnectedportion 301 and then patterning (developing) the resist film 309.

[0203] Then, as shown in FIG. 24B, the formation of the contact holes107, 111 and the window opening of the terminal portion (not shown) arecarried out by the selective etching using the dry etching. At the sametime, by selectively etching the inside of the holes 311, 313, an uppersurface of the disconnection end portion of the gate bus line 103 a isexposed, and also the disconnection repairing contact holes 315, 317reaching the surface of the glass substrate 121 is formed on both sidesof the gate bus line 103 a in the width direction.

[0204] Then, as shown in FIG. 24C, a laser CVD film 307 for connectingthe gate bus line 103 a in the disconnection repairing contact holes315, 317 is formed by the laser CVD method. Then, the pixel electrode113 is formed by forming the film of the transparent electrode materialsuch as ITO, etc. on the overall surface of the substrate and thenpatterning the film.

[0205] In this manner, as shown in FIG. 23, one disconnection endportion and the other disconnection end portion of the gate bus line 103a are connected electrically by the laser CVD film 307 that is formedbetween the disconnection repairing contact holes 315, 317. Thus, thedisconnection fault can be repaired.

[0206] According to this example 5, since the disconnection repairingcontact holes are formed by dry-etching the insulating film before theformation of the pixel electrode, such disconnection repairing contactholes can be formed with good precision, without the contamination ofthe pixel electrode caused by the laser beam irradiation, unlike theprior art. Also, the repairing operation can be carried out not toincrease the number of masks.

[0207] In addition, since the disconnection repairing contact holes areformed to have the width larger than the data bus line, the contact areacan be spread and the reliability of connection can be enhanced ratherthan the case where the contact holes are formed only on the wiringpattern.

[0208] In this case, the connection of the wirings by the laser CVDmethod may be carried out after the pixel electrode has been formed.

EXAMPLE 6

[0209]FIG. 25 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. FIG. 25 shows pixel electrodes 113 a, 113 b, 113 c,113 d in four pixel areas that are defined by three data bus lines 111a, 101 b, 101 c and two gate bus lines 103 a, 103 b. A storagecapacitance bus line 115 a or 115 b is formed in each pixel area.

[0210]FIG. 25 shows such a situation that the gate bus line 103 a isdisconnected at a disconnected portion 321 that extends over two pixelareas to put the data bus line 101 b between them.

[0211] In this example 6, first, disconnection repairing contact holes323, 325 whose width is larger than the width of the gate bus line 103 aare formed on disconnection end portions of the gate bus line 103 alocated on both sides of the disconnected portion 321 respectively.Then, a laser CVD film 327 that connects the gate bus line 103 a in thedisconnection repairing contact hole 323 and the left side end of thepixel electrode 113 c is formed, and similarly a laser CVD film 329 thatconnects the gate bus line 103 a in the disconnection repairing contacthole 325 and the left side end of the pixel electrode 113 d is formed.Also, a laser CVD film 331 that directly connects the pixel electrode113 c and the pixel electrode 113 d. In this case, prior to theformation of the pixel electrodes 113 a to 113 d, the drain electrode117 a of the TFT connected to the pixel electrode 113 c is separatedfrom the data bus line 101 a by irradiating the laser beam to a cuttingposition 333 at the root portion of the drain electrode 117 a so as tocut off the connection to the data bus line 101 a. Similarly, the drainelectrode 117 b of the TFT connected to the pixel electrode 113 d isseparated from the data bus line 101 b by irradiating the laser beam toa cutting position 335 at the root portion of the drain electrode 117 bso as to cut off the connection to the data bus line 101 b.

[0212] As a result, one disconnection end portion of the gate bus line103 a is connected to the pixel electrode 113 c via the laser CVD film327 in the disconnection repairing contact hole 323, and the otherdisconnection end portion of the gate bus line 103 a is connected to thepixel electrode 113 d via the laser CVD film 329 in the disconnectionrepairing contact hole 325, and the pixel electrode 113 c and the pixelelectrode 113 d are connected by the laser CVD film 331. Therefore, theelectrical connection can be routed to detour the disconnected portion321 of the gate bus line 103 a. In addition, since the disconnectionrepairing contact holes 323, 325 are formed in the same way as the aboveexamples, the electrical connection with the high reliability can beobtained similarly.

EXAMPLE 7

[0213]FIG. 26 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. In FIG. 26, three data bus lines 101 a, 101 b, 101 cand two gate bus lines 103 a, 103 b are shown, and also two pixel areas(pixel electrodes 113 a, 113 b) defined by these bus lines are shown.Also, a storage capacitance bus line 115 is formed between the gate buslines 103 a and 103 b. In FIG. 26, the storage capacitance bus line 115is disconnected at a disconnected portion 341 in the area of the pixelelectrode 113 a.

[0214] First, disconnection repairing contact holes 343, 345 whose widthis larger than the width of the storage capacitance bus line 115respectively are formed on the storage capacitance bus line 115 in areasbetween the pixel electrode 113 a and the data bus lines 101 a, 101 b onboth sides of the disconnected portion 341 to traverse the storagecapacitance bus line 115.

[0215] The storage capacitance bus line 115 containing its side surfacesare exposed in the disconnection repairing contact holes 343, 345. Then,laser CVD films 347, 349 that connects the pixel electrode 113 a and thestorage capacitance bus line 115 in the disconnection repairing contacthole 343 and the pixel electrode 113 a and the storage capacitance busline 115 in the disconnection repairing contact hole 345 respectivelyare formed. In this case, prior to the formation of the pixel electrode113 a, the drain electrode 117 a of the TFT connected to the pixelelectrode 113 a is separated from the data bus line 101 a by irradiatingthe laser beam to a cutting position 351 at the root portion of thedrain electrode 117 a so as to cut off the connection to the data busline 101 a.

[0216] In this manner, the disconnection fault occurred in the gate busline can be repaired without fail.

[0217] The disconnection repairing method in the example 7 will beexplained in more detail with reference to FIGS. 27A to 27D hereunder.FIGS. 27A to 27D show a sectional shape in vicinity of the storagecapacitance bus line 115 taken along a U-U′ line in FIG. 26respectively. First, it is on the assumption that the disconnectioninspection of the storage capacitance bus line 115 has been carried outbefore the contact holes 107, 111 shown in FIG. 26 are formed, and thatthe disconnected portion 341 of the storage capacitance bus line 115shown in FIG. 26 is found as the result of the disconnection inspection.

[0218] In order to form the contact holes 107 and 111, a resist film 353is formed by coating the photoresist on the overall surface of thesubstrate. Then, as shown in FIG. 27A, holes 355, 357 that have a widthlarger than the width of the storage capacitance bus line 115respectively are formed by applying the spot-exposure or the laser beamirradiation to the resist film 353 on the disconnection end portions ofthe storage capacitance bus line 115 on both sides of the disconnectedportion 341 and then patterning (developing) the resist film 353.

[0219] Then, as shown in FIG. 27B, the formation of the contact holes107, 111 and the window opening of the terminal portion (not shown) arecarried out by the selective etching using the dry etching. At the sametime, by selectively etching the inside of the holes 355, 357, the uppersurface of the disconnection end portion of the storage capacitance busline 115 is exposed, and also the disconnection repairing contact holes361, 363 reaching the surface of the glass substrate 121 are formed onboth sides of the storage capacitance bus line 115 in the widthdirection.

[0220] Then, as shown in FIG. 27C, the pixel electrode 113 is formed byforming the film of the transparent electrode material such as ITO, etc.on the overall surface of the substrate and then patterning the film.Then, as shown in FIG. 27D, laser CVD films 347, 349 for connecting thepixel electrode 113 a and the storage capacitance bus line 115 in thedisconnection repairing contact holes 361, 363 respectively are formedby the laser CVD method.

[0221] In this manner, as shown in FIG. 26, one disconnection endportion and the other disconnection end portion of the storagecapacitance bus line 115 are connected electrically by the laser CVDfilms 347, 349 that are formed between the pixel electrode 113 a and thedisconnection repairing contact holes 361, 363. Thus, the disconnectionfault can be repaired.

[0222] According to this example 7, since the disconnection repairingcontact holes are formed by dry-etching the insulating film prior to theformation of the pixel electrode, such disconnection repairing contactholes can be formed with good precision, without the contamination ofthe pixel electrode caused by the laser beam irradiation, unlike theprior art. Also, the repairing operation can be carried out not toincrease the number of masks.

[0223] In addition, since the disconnection repairing contact holes areformed to have the width larger than the storage capacitance bus line115, the contact area can be expanded and the reliability of connectioncan be enhanced rather than the case where the contact holes are formedonly on the wiring pattern.

EXAMPLE 8

[0224]FIG. 28 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. FIG. 28 shows the pixel electrodes 113 a, 113 b intwo pixel areas that are defined by three data bus lines 101 a, 101 b,101 c and two gate bus lines 103 a, 103 b. The storage capacitance busline 115 is formed in each pixel area.

[0225]FIG. 28 shows such a situation that the storage capacitance busline 115 is disconnected at a disconnected portion 371 that extends overtwo pixel areas between which the data bus line 101 b is put.

[0226] In this example 8, first a disconnection repairing contact hole373 whose width is larger than the width of the storage capacitance busline 115 is formed on the storage capacitance bus line 115 in the areabetween the pixel electrode 113 a and the data bus line 101 a on bothsides of the disconnected portion 371. Similarly, a disconnectionrepairing contact hole 375 whose width is larger than the width of thestorage capacitance bus line 115 is formed on the storage capacitancebus line 115 in the area between the pixel electrode 113 b and the databus line 101 c. The storage capacitance bus line 115 containing its sidesurfaces are exposed in the disconnection repairing contact holes 373,375.

[0227] Then, laser CVD films 377, 379 that connect the pixel electrode113 a and the storage capacitance bus line 115 in the disconnectionrepairing contact hole 373 and the pixel electrode 113 c and the storagecapacitance bus line 115 in the disconnection repairing contact hole 375respectively are formed. In addition, a laser CVD film 381 that directlyconnects the pixel electrode 113 a and the pixel electrode 113 b.

[0228] In this case, prior to the formation of the pixel electrode 113a, the drain electrode 117 a of the TFT connected to the pixel electrode113 a is separated from the data bus line 101 a by irradiating the laserbeam to a cutting position 383 at the root portion of the drainelectrode 117 a to cut off the connection to the data bus line 101 a.Similarly, the drain electrode 117 b of the TFT connected to the pixelelectrode 113 b is separated from the data bus line 101 b by irradiatingthe laser beam to a cutting position 385 at the root portion of thedrain electrode 117 b to cut off the connection to the data bus line 101b.

[0229] As the result of the above, one disconnection end portion of thestorage capacitance bus line 115 is connected to the pixel electrode 113a via the laser CVD film 377 in the disconnection repairing contact hole373, and the other disconnection end portion of the storage capacitancebus line 115 is connected to the pixel electrode 113 b via the laser CVDfilm 379 in the disconnection repairing contact hole 375, and the pixelelectrode 113 a and the pixel electrode 113 b are connected by the laserCVD film 381. Therefore, the electrical connection can be routed todetour the disconnected portion 371 of the gate bus line 115. Inaddition, since the disconnection repairing contact holes 373, 375 areformed in the same way as the above examples, the electrical connectionwith the high reliability can be obtained similarly.

EXAMPLE 9

[0230]FIG. 29 shows a substrate surface when a lead wiring forming areaof the gate bus lines and the data bus lines on the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside. In FIG. 29, the configuration in which the gate bus lines and thedata bus lines 391 in the display area are connected to an externalconnection terminal portion 395 via lead wirings 393 is shown.

[0231] In FIG. 29, one of the lead wirings 393 is disconnected at adisconnected portion 397. In this example 9, disconnection repairingcontact holes 413, 415 whose width is larger than the width of the leadwiring 393 are formed on disconnection end portions of the lead wiring393 on both sides of the disconnected portion 393 to traverse the leadwiring 393. Then, a laser CVD film 405 that connects the lead wiring 393in the disconnection repairing contact hole 413 and the lead wiring 393in the disconnection repairing contact hole 415 is formed.

[0232] The disconnection repairing method in the example 9 will beexplained in more detail with reference to FIGS. 30A to 30C hereunder.FIGS. 30A to 30C show a sectional shape in vicinity of the lead wiring393 taken along a V-V′ line in FIG. 29 respectively. It is on theassumption that the disconnection inspection of the lead wiring 393 hasbeen carried out before the contact holes 107 and 111 (not shown) areformed, and that the disconnected portion 397 of the lead wiring 393shown in FIG. 29 is found as the result of the disconnection inspection.

[0233] In order to form the contact holes 107 and 111, a resist film 407is formed by coating the photoresist on the overall surface of thesubstrate. Then, as shown in FIG. 30A, holes 409, 411 that have a widthlarger than the width of the lead wiring 393 respectively are formed byapplying the spot-exposure or the laser beam irradiation to the resistfilm 407 on the disconnection end portions of the lead wiring 393 onboth sides of the disconnected portion 397 and then patterning theresist film 407.

[0234] Then, as shown in FIG. 30B, the formation of the contact holes107, 111 and the window opening of the terminal portion (not shown) arecarried out by the selective etching using the dry etching. At the sametime, by selectively etching the inside of the holes 409, 411, the uppersurface of the disconnection end portion of the lead wiring 393 isexposed and also the disconnection repairing contact holes 413, 415reaching the surface of the glass substrate 121 are formed on both sidesof the lead wiring 393 in the width direction.

[0235] Then, the pixel electrode 113 (not shown) is formed by formingthe film of the transparent electrode material such as ITO, etc. on theoverall surface of the substrate and then patterning the film. Then, asshown in FIG. 30C, a laser CVD film 405 for connecting the lead wiring393 in the disconnection repairing contact holes 413 and the lead wiring393 in the disconnection repairing contact hole 415 is formed by thelaser CVD method.

[0236] In this manner, as shown in FIG. 29, one disconnection endportion and the other disconnection end portion of the lead wiring 393are connected electrically by the laser CVD film 405 that is formedbetween the disconnection repairing contact holes 413, 415. Thus, thedisconnection fault can be repaired.

[0237] According to this example 9, since the disconnection repairingcontact holes are formed by dry-etching the insulating film prior to theformation of the pixel electrode, such disconnection repairing contactholes can be formed with good precision, without the contamination ofthe pixel electrode caused by the laser beam irradiation, unlike theprior art. Also, the repairing operation can be carried out not toincrease the number of masks.

[0238] In addition, since the disconnection repairing contact holes areformed to have the width larger than the lead wiring 393, the contactarea can be widened and the reliability of connection can be increasedrather than the case where the contact holes are formed only on thewiring pattern.

EXAMPLE 10

[0239]FIG. 31 shows a substrate surface when the TFT substrate of theliquid crystal display panel is viewed from the liquid crystal layerside, like FIG. 9. In FIG. 31, three data bus lines 111 a, 101 b, 101 cand three gate bus lines 103 a, 103 b, 103 c are shown, and also fourpixel areas (pixel electrodes 113 a, 113 b, 113 c, 113 d) defined bythese bus lines are shown. Also, a storage capacitance bus line 115 a isshown between the gate bus lines 103 a and 103 b, and a storagecapacitance bus line 115 b is shown between the gate bus lines 103 b and103 c.

[0240] In FIG. 31, the data bus line 101 b is disconnected at adisconnected portion 421 between the pixel electrode 113 a and the pixelelectrode 113 a. The gate bus line 103 b is disconnected at adisconnected portion 423 located at a right upper end of the pixelelectrode 113 c. Also, the storage capacitance bus line 115 b isdisconnected at a disconnected portion 425 that extends over two areaslocated between the pixel electrode 113 c and the pixel electrode 113 d.

[0241] In this case, laser CVD films 427, 429, 431 that are wider thanthe line width of the disconnected portion are formed on the protectionfilm, that is located immediately on both end portions of thedisconnected portions 421, 423, 425, respectively. Then, laser weldingportions indicated by a black mark are formed on both end portions ofrespective disconnected portions by the laser welding method, anddisconnection ends of the disconnected wiring patterns are directlyconnected by the laser CVD films 427, 429, 431.

[0242] Then, the fault repairing method in the example 10 will beexplained particularly with reference to FIGS. 32A and 32B, FIGS. 33Aand 33B, and FIGS. 34A and 34B hereunder. FIGS. 32A and 32B show asectional shape in vicinity of the data bus line 101 b taken along aW-W′ line shown in FIG. 31 respectively. FIGS. 33A and 33B show asectional shape in vicinity of the gate bus line 103 b taken along anX-X′ line shown in FIG. 31 respectively. FIGS. 34A and 34B show asectional shape in vicinity of the storage capacitance bus line 115 btaken along a Y-Y′ line shown in FIG. 31 respectively.

[0243] First, as shown in FIG. 32A, FIG. 33A and FIG. 34A, the laser CVDfilms 427, 429, 431 that have a width larger than the disconnectedportions 421, 423, 425 respectively are formed on the protectioninsulating film 133 to cover the disconnected portions 421, 423, 425.Then, as shown in FIG. 32B, FIG. 33B and FIG. 34B, the laser weldingportions are formed on both end portions of the disconnected portions421, 423, 425 by applying the laser welding method to irradiate thelaser beam (e.g., YAG laser beam) to both end portions of thedisconnected portions 421, 423, 425 from the back surface side or thefront surface side.

[0244] As shown in FIG. 32B, the laser CVD film 427 and the data busline 101 b are connected by the laser welding portions 433, 434 at thedisconnected portion 421, and thus the disconnection caused at thedisconnected portion 421 can be repaired. As shown in FIG. 33B, thelaser CVD film 429 and the gate bus line 103 b are connected by thelaser welding portions 435, 436 at the disconnected portion 423, andthus the disconnection caused at the disconnected portion 423 can berepaired. As shown in FIG. 34B, the laser CVD film 431 and the storagecapacitance bus line 115 b are connected by the laser welding portions437, 438 at the disconnected portion 425, and thus the disconnectioncaused at the disconnected portion 425 can be repaired.

[0245] As a result, the disconnected portion 421 is connectedelectrically between one disconnection end portion of the data bus line101 b and the other disconnection end portion of the data bus line 101 bvia the laser welding portion 433, the laser CVD film 427, and the laserwelding portion 434. The disconnected portion 423 is connectedelectrically between one disconnection end portion of the gate bus line103 b and the other disconnection end portion of the gate bus line 103 bvia the laser welding portion 435, the laser CVD film 429, and the laserwelding portion 436. Also, the disconnected portion 425 is connectedelectrically between one disconnection end portion of the storagecapacitance bus line 115 b and the other disconnection end portion ofthe storage capacitance bus line 115 b via the laser welding portion437, the laser CVD film 431, and the laser welding portion 438.

[0246] Here, if the above-mentioned disconnection repairing method isemployed in the disconnected portion 425, the right side end of thepixel electrode 113 c and the left side end of the pixel electrode 113 dare connected. For this reason, the drain electrode 117 a of the TFTconnected to the pixel electrode 113 c and the drain electrode 117 b ofthe TFT connected to the pixel electrode 113 d must be separated fromthe data bus lines 101 a, 101 b respectively.

[0247] (Second Embodiment)

[0248] Next, a liquid crystal display device and its fault repairingmethod according to a second embodiment of the present invention will beexplained with reference to FIG. 35A to FIG. 53 hereunder. FIGS. 35A to35D are views showing the principle of the fault repairing method forliquid crystal display device according to the second embodiment of thepresent invention. FIG. 35A shows the display panel in which a gate busline 502 is formed on a transparent glass substrate 500, then a data busline 506 is formed on the gate bus line 502 via an insulating film (gateinsulating film; SiN) 504 to intersect with the gate bus line 502, andthen an insulating film (protection film; SiN) 508 is formed on the gatebus line 502. In addition, FIG. 35A shows the situation thatshort-circuit between the gate bus line 502 and the data bus line 506occurs at an interlayer short-circuit portion 510.

[0249] As shown in FIG. 35B, the data bus line 506 is cut off atdisconnected portions 512, 514 by irradiating the laser beam to bothsides, between which the interlayer short-circuit portion 510 issandwiched, from the uppermost layer insulating film (SiN) 508 along thedata bus line 506.

[0250] Then, as shown in FIG. 35C, contact holes 516, 518 are formed byirradiating the laser beam onto the insulating (SiN) film 508 located onthe outside of the disconnected portions 512, 514 respectively to exposethe data bus line 506.

[0251] Then, as shown in FIG. 35D, metal deposition portions 520, 522are formed by forming a metal film on respective inner peripheries ofthe contact holes 516, 518 and on the insulating layer 508 around theopening portions by virtue of the laser CVD method. Then, the metaldeposition portions 520 and 522 formed on the insulating film 508 areconnected electrically by any one of methods (A) to (E) described in thefollowing.

[0252] (A) The metal deposition portions 520 and 522 are connecteddirectly by the metal film, that is formed by the laser CVD method,subsequently when the metal deposition portions 520 and 522 are formedon the insulating layer 508.

[0253] (B) The spare wiring having a predetermined length is formedpreviously on the side of the data bus line 506, then the contact holesthat are opened the uppermost layer insulating film 508 on both ends ofthe spare wiring is provided, and then the contact holes in the sparewiring and the metal deposition portions 520 and 522 are connected bythe metal film that is formed by the CVD method.

[0254] (C) The pixel electrode and the metal deposition portions 520 and522 are connected by the metal film that is formed by the CVD method.

[0255] (D) The contact holes 516, 518 in FIG. 35C are not provided.Spare pads are extended previously to the outside of both disconnectedportions of the data bus line 506 respectively, then contact holes to beopened in the uppermost layer insulating film 508 are provided on thespare pads, and then both contact holes are connected by the metal filmformed by the laser CVD method.

[0256] (E) After the contact holes 516, 518 in FIG. 35C are notprovided, the transparent conductive film that is connected to thecontact holes 516, 518 is formed as the spare pads on the insulatinglayer 508 on the outside ends of both disconnected portions of the databus line respectively, and then both spare pads are connected by themetal film formed by the laser CVD method.

[0257] Accordingly, the disconnected end portions of the disconnecteddata bus line 506 are connected by the metal film that is drawn on theinsulating film 508 by the laser CVD method, and thus the interlayershort-circuit can be repaired. The case where the interlayershort-circuit is repaired when the data bus line 506 is disconnected isexplained above. However, it is needless to say that the interlayershort-circuit can be repaired when not the data bus line 506 but thegate bus line 502 or the storage capacitance bus line (not shown) isdisconnected similarly.

[0258] In this manner, according to the second embodiment of the presentinvention, since the interlayer short-circuit portion (line faultportion) can be repaired by drawing the wiring by virtue of the laserCVD method, the line fault can be repaired in the display area. Thefault repairing method according to the second embodiment will beexplained with reference to respective examples hereunder.

[0259] In the following examples, the laser beam employed to form thecontact holes is the third harmonic (wavelength 355 nm) or the fourthharmonic (wavelength 266 nm) of the YAG pulse laser. Also, the metalfilm formed by the laser CVD method is deposited by irradiating thecontinuous laser beam of the wavelength 355 nm, that is output from theYAG laser, after the concentration of the organic metal gas (filmforming gas), the laser power, the scanning rate, and the number oftimes of scanning are adjusted while flowing the Ar gas containing W(tungsten) organic metal, Mo (molybdenum) organic metal, or Cr(chromium) organic metal.

[0260] The particular film forming conditions will be given as follows.The film forming gas is metal carbonyl {W(CO)₆,Cr(CO)₆}. The laser poweris 0.2 to 0.4 as the attenuator value. The scanning rate is 3.0 m/sec.The number of times of scanning is one. The flow rate of the carrier gas(Ar) is 90 cc/min. If the film is formed under these conditions, the W(tungsten) film having the thickness of 400 to 600 nm and the specificresistance of 100 to 150 μm can be obtained. In this case, the specificresistance of W single substance is 5.65 μΩcm.

[0261] The diameter of the contact hole is set to the level of 2 to 5 μmalthough it depends on the conditions in laser irradiation. According tothe metal wiring formed by the laser CVD method, the minimum drawingline width is 5 μm, the film thickness is 0.2 μm, and the specificresistance is less than 50 μΩcm. It has been checked that, when theliquid crystal display device is constructed by repairing the interlayershort-circuit under these conditions, no problem occurs.

EXAMPLE 1

[0262]FIG. 36 shows a substrate surface when the interlayershort-circuit portion of the amorphous silicon (a-Si) TFT substrate ofthe liquid crystal display device is viewed from the liquid crystallayer side. FIG. 36 shows two data bus lines 506 a, 506 b and one gatebus line 502, and also two pixel areas (pixel electrodes 524 a, 524 b)are defined by these bus lines. Also, a storage capacitance bus line 526is formed to traverse laterally lower portions of two pixel electrodes524 a, 524 b.

[0263] In FIG. 36, a data bus line 506 a is short-circuited to a gatebus line 502 at an interlayer short-circuit portion 510 a. Also, thedata bus line 506 a is short-circuited to a storage capacitance bus line526 at an interlayer short-circuit portion 510 b.

[0264] In this case, in order to repair the interlayer short-circuits ofthe gate bus line 502 and the data bus line 506 a on the insulatingsubstrate, first the data bus line 506 a is disconnected at disconnectedportions 512 a, 512 b by irradiating the laser beam onto both sides ofthe interlayer short-circuit portion 510 a of the data bus line 506 a(see FIG. 35A). Then, contact holes 516 a, 516 b are formed respectivelyby irradiating the YAG pulse laser beam onto both sides of theinterlayer short-circuit portion 510 a from the uppermost layerinsulating film (SiN) 508 to expose the data bus line 506 a (see FIG.35B). Then, a metal wiring for connecting the contact holes 516 a and516 b is formed by the laser CVD method. In this case, if the metalwiring is formed to connect the contact holes 516 a and 516 b like astraight line, the data bus line 506 a and the gate bus line 502 areshort-circuited again via the disconnected portions 512 a, 512 b.

[0265] Therefore, as shown in FIG. 36, the contact holes 516 a and 516 bare connected by forming metal wirings 528 a, 528 b, 528 c to detour thedisconnected portions 512 a, 512 b of the data bus line 506 a, and thusthe interlayer short-circuit can be repaired. The disconnectionrepairing method according to the example 1 will be explained moreparticularly with reference to FIG. 37 and FIG. 38 hereunder.

[0266]FIG. 37 shows a sectional shape of the TFT taken along an A-A′line in FIG. 36. FIG. 38 shows a sectional shape of the TFT taken alonga B-B′ line in FIG. 36. As shown in FIG. 37, the contact hole 516 b (516a) provided on the data bus line 506 a is filled with the metal film byvirtue of the laser CVD method and also a metal wiring 528 a (528 b) isformed by extending the metal film formed by the laser CVD method by apredetermined length in the direction that intersects orthogonally withthe data bus line 506 a. Then, a metal wiring 528 c that connects endportions of the metal wirings 528 a, 528 b extended from the contactholes 516 b, 516 a is formed by the laser CVD method. Then, as shown inFIG. 38, the metal wiring 528 c is provided to cross the gate bus line502.

[0267] As a result, one end of the disconnected portion of the data busline 506 a can be connected electrically to the other end of thedisconnected portion of the data bus line 506 a via the contact hole 516a, the metal wiring 528 b, the metal wiring 528 c, and the contact hole516 b, and thus the interlayer short-circuit can be repaired.

[0268] Also, in FIG. 36, in order to repair the interlayer short-circuitbetween the storage capacitance bus line 526 and the data bus line 506 aon the insulating substrate, disconnected portions 512 c, 512 d areformed by irradiating the laser beam onto both sides of the interlayershort-circuit portion 510 b of the data bus line 506 a (see FIG. 35A).Then, contact holes 516 c, 516 d are formed respectively by irradiatingthe YAG pulse laser beam onto both sides of the interlayer short-circuitportion 510 a from the uppermost layer insulating film (SiN) 508 toexpose the data bus line 506 a (see FIG. 35B). Then, like the above,metal wirings 530 a, 530 b are formed by the laser CVD method to detourthe disconnected portions 512 c, 512 d of the data bus line 506 a, andthen the interlayer short-circuit can be repaired by connecting thecontact holes 516 c and 516 d via the metal wirings 530 a, 530 b.

EXAMPLE 2

[0269]FIG. 39 shows a substrate surface when the interlayershort-circuit portion of the TFT substrate of the liquid crystal displaydevice is viewed from the liquid crystal layer side. In FIG. 39, twodata bus lines 506 a, 506 b and one gate bus line 502 are shown, andalso two pixel areas (pixel electrodes 524 a, 524 b) defined by thesebus lines are shown. Also, the storage capacitance bus line 526 is shownto traverse laterally middle portions of two pixel electrodes 524 a, 524b.

[0270] In this example 2, in the intersection area between the data busline 506 and the gate bus line 502, a spare wiring 532 having apredetermined length is formed between the pixel electrode 524 and theneighboring data bus line 506 along the data bus line 506 to traversethe gate bus line 502. Also, in the intersection area between the databus line 506 and the storage capacitance bus line 526, a spare wiring532 having a predetermined length is formed between the pixel electrode524 and the neighboring data bus line 506 on the side of the data busline 506 to traverse the storage capacitance bus line 526.

[0271] For example, in the intersection area between the data bus line506 b and the gate bus line 502, a spare wiring 532 c having apredetermined length is formed between the pixel electrode 524 a and theneighboring data bus line 506 b on the data bus line 506 to traverse thegate bus line 502. Also, for example, in the intersection area betweenthe data bus line 506 and the storage capacitance bus line 526, a sparewiring 532 d having a predetermined length is formed between the pixelelectrode 524 and the neighboring data bus line 506 b on the side of thedata bus line 506 to traverse the storage capacitance bus line 526.

[0272] In FIG. 39, like the example 1 of the second embodiment, the databus line 506 a is short-circuited to the gate bus line 502 at theinterlayer short-circuit portion 510 a. Also, the data bus line 506 a isshort-circuited to the storage capacitance bus line 526 at theinterlayer short-circuit portion 510 b.

[0273] First, the repairing method of the interlayer short-circuitportion 510 a will be explained hereunder. In this example 2, like theexample 1, the data bus line 506 a is disconnected at the disconnectedportions 512 a, 512 b, and then the contact holes 516 a, 516 b areformed respectively by irradiating the laser beam onto the insulatingfilm 508 on the data bus line 502 a in vicinity of the disconnectedportions 512 a, 512 b. Also, the contact holes 534 a, 534 b are formedby irradiating the laser beam onto the insulating film 508 on both endportions of the spare wiring 532 a.

[0274] Then, a metal wiring 536 a for connecting the contact holes 516 aand 516 b is formed by the laser CVD method. Similarly, a metal wiring536 b for connecting the contact holes 516 b and 534 b is formed by thelaser CVD method.

[0275] More particularly, the interlayer short-circuit is repaired incompliance with procedures shown in FIG. 40 and FIG. 41 hereunder. FIG.40 shows a sectional shape taken along a C-C′ line in FIG. 39. FIG. 41shows a sectional shape taken along a D-D′ line in FIG. 39. As shown inFIG. 40 and FIG. 41, a spare wiring 532 a is formed previously by stepsapplied to form the data bus line 506 a. If the interlayer short-circuitto the gate bus line 502 is caused, the contact holes 516 a (516 b), 534a (534 b) are formed on the data bus line 506 a and the spare wiring 532a respectively. Then, the contact holes 516 a and 534 a (the contactholes 516 b and 534 b) are connected by the metal wiring 536 a (536 b)to bury them.

[0276] As a result, as shown in FIG. 41, since the spare wiring 532 a isformed to cross the gate bus line 502, the detouring circuit reachingthe metal wiring 536 b from the metal wiring 536 a via the spare wiring532 a is constructed, and thus the interlayer short-circuit 510 abetween the data bus line 506 a and the gate bus line 502 can berepaired. According to this example 2, since merely the metal wirings536 a, 536 b are drawn by the laser CVD method, the areas that are drawnby the laser CVD method can be shortened.

[0277] Similarly to the interlayer short-circuit 510 b, the contactholes 516 c, 516 d, 538 a, 538 b are formed respectively, and then theinterlayer short-circuit 510 b between the data bus line 506 a and thestorage capacitance bus line 526 can be repaired by connecting thecontact holes 516 c and 538 a by the metal wiring 540 a and alsoconnecting the contact holes 516 d and 538 b by the metal wiring 540 b.

EXAMPLE 3

[0278]FIG. 42 shows a substrate surface when the interlayershort-circuit portion of the TFT substrate of the liquid crystal displaydevice is viewed from the liquid crystal layer side. In FIG. 42, twodata bus lines 506 a, 506 b and one gate bus line 502 are shown, and twopixel areas (pixel electrodes 524 a, 524 b) are defined by these buslines. Also, the storage capacitance bus line 526 is shown to traverselaterally middle portions of two pixel electrodes 524 a, 524 b.

[0279] In this example 3, in the intersection area between the data busline 506 a and the gate bus line 502, a spare wiring 542 a having apredetermined length is formed on the side of the gate bus line 502 totraverse the data bus line 506 a. Also, in the intersection area betweenthe data bus line 506 a and the storage capacitance bus line 526, aspare wiring 542 c having a predetermined length is formed on the sideof the storage capacitance bus line 526 to traverse the storagecapacitance bus line 526.

[0280] Similarly, in the intersection area between the data bus line 506b and the gate bus line 502, a spare wiring 542 b having a predeterminedlength is formed on the side of the gate bus line 502 to traverse thedata bus line 506 b. Also, in the intersection area between the data busline 506 b and the storage capacitance bus line 526, a spare wiring 542d having a predetermined length is formed on the side of the storagecapacitance bus line 526 to traverse the data bus line 506 b. Thesespare wirings 542 a to 542 d are formed not to contact to theneighboring pixel electrode.

[0281] In FIG. 42, like the example 1 of the second embodiment, the databus line 506 a is short-circuited to the data bus line 502 at theinterlayer short-circuit portion 510 a. Also, the data bus line 506 a isshort-circuited to the storage capacitance bus line 526 at theinterlayer short-circuit portion 510 b.

[0282] First, the repairing method of the interlayer short-circuitportion 510 a will be explained hereunder. In this example 3, the gatebus line 502 is disconnected at the disconnected portions 512 a, 512 b,and the contact holes 516 a, 516 b are formed respectively byirradiating the laser beam onto the insulating film 508 in vicinity ofthe disconnected portions 512 a, 512 b. Also, contact holes 544 a, 544 bare formed by irradiating the laser beam onto the insulating film 508 onboth end portions of the spare wiring 542 a.

[0283] Then, a metal wiring 546 a for connecting the contact holes 516 aand 544 a is formed by the laser CVD method. Similarly, a metal wiring546 b for connecting the contact holes 516 b and 544 b is formed by thelaser CVD method.

[0284] More particularly, the interlayer short-circuit is repaired incompliance with procedures shown in FIG. 43 and FIG. 44 hereunder. FIG.43 shows a sectional shape taken along an E-E′ line in FIG. 42. FIG. 44shows a sectional shape taken along an F-F′ line in FIG. 42. As shown inFIG. 43 and FIG. 44, a spare wiring 542 a is formed previously by stepsapplied to form the gate bus line 502. If the interlayer short-circuitto the data bus line 506 a is caused, the contact holes 516 a (516 b),544 a (544 b) are formed on the gate bus line 502 and the spare wiring542 a respectively. Then, the contact holes 516 a and 544 a (the contactholes 516 b and 544 b) are connected by the metal wiring 546 a (546 b)to bury them.

[0285] As a result, since the spare wiring 542 a is formed to cross thegate bus line 502, the detouring circuit reaching the metal wiring 546 bfrom the metal wiring 546 a via the spare wiring 542 a is constructed,and thus the interlayer short-circuit 510 a between the data bus line506 a and the data bus line 502 can be repaired. According to thisexample 3, since merely the metal wirings 546 a, 546 b are drawn by thelaser CVD method, the areas that are drawn by the laser CVD method canbe shortened, like the example 2.

[0286] Similarly to the interlayer short-circuit 510 b, the contactholes 516 c, 516 d, 538 a, 538 b are formed respectively, and then theinterlayer short-circuit 510 b between the data bus line 506 a and thestorage capacitance bus line 526 can be repaired by connecting thecontact holes 516 c and 548 a by the metal wiring 550 a and alsoconnecting the contact holes 516 d and 548 b by the metal wiring 550 b.

EXAMPLE 4

[0287]FIG. 45 shows a substrate surface when the interlayershort-circuit portion of the TFT substrate of the liquid crystal displaydevice is viewed from the liquid crystal layer side. In FIG. 45, twodata bus lines 506 a, 506 b and one gate bus line 502 are shown, and twopixel areas (pixel electrodes 524 a, 524 b) defined by these bus linesare shown. Also, the storage capacitance bus line 526 is shown totraverse laterally middle portions of two pixel electrodes 524 a, 524 b.

[0288] In this example 4, near the intersection area between the databus line 506 a and the gate bus line 502, spare pads 552 a, 552 b havinga predetermined length are provided on the side portions of the data busline 506 a on both sides of the gate bus line 502 in the widthdirection. Also, spare pads 564 a, 564 b having a predetermined lengthare provided similarly on the side portions of the data bus line 506 b.In addition, near the intersection area between the data bus line 506 aand the storage capacitor bus line 526, spare pads 558 a, 558 b having apredetermined length are provided on the side portions of the data busline 506 a on both sides of the storage capacitance bus line 526 in thewidth direction. Also, spare pads 566 a, 566 b having a predeterminedlength are provided similarly on the side portions of the data bus line506 b.

[0289] In FIG. 45, like the example 1, the data bus line 506 a isshort-circuited to the data bus line 502 at the interlayer short-circuitportion 510 a. Also, the data bus line 506 a is short-circuited to thestorage capacitance bus line 526 at the interlayer short-circuit portion510 b.

[0290] First, the repairing method of the interlayer short-circuitportion 510 a will be explained hereunder. In this example 4, the databus line 506 a is disconnected at the disconnected portions 512 a, 512b, and the contact holes 516 a, 516 b are formed respectively byirradiating the laser beam onto the insulating film 508 in vicinity ofthe disconnected portions 512 a, 512 b. Also, contact holes 554 a, 554 bare formed by irradiating the laser beam onto the insulating film 508 onthe spare pads 552 a, 552 b. Then, a metal wiring 556 for connecting thecontact holes 554 a and 554 b is formed by the laser CVD method.

[0291] More particularly, the interlayer short-circuit is repaired incompliance with procedures shown in FIG. 46 and FIG. 47 hereunder. FIG.46 shows a sectional shape of the TFT taken along a G-G′ line in FIG.45. FIG. 47 shows a sectional shape of the TFT taken along an H-H′ linein FIG. 45. As shown in FIG. 46 and FIG. 47, spare pads 552 a, 552 b areformed previously by steps applied to form the data bus line 506 a. Ifthe interlayer short-circuit occurs between the data bus line 506 a andthe gate bus line 502, the contact holes 554 a, 554 b are formed on thespare pads 552 a and 552 b respectively. Then, the metal wiring 556 forconnecting the contact holes 554 a and 554 b is formed by the laser CVDmethod.

[0292] As a result, the detouring circuit reaching the spare pad 552 bfrom the spare pad 552 a via the metal wiring 556 is constructed, andthus the interlayer short-circuit 510 a between the data bus line 506 aand the data bus line 502 can be repaired. According to this example 4,since the contact holes are provided merely on the spare pads 552 a, 552b, the simplification of the repairing operation can be achieved ratherthan the case of the examples 2, 3 in which the spare wirings are alsoprovided.

[0293] Similarly to the interlayer short-circuit 510 b, since thecontact holes 560 c and 560 b provided on the spare pads 558 a, 558 bare connected via the metal wiring 562, the interlayer short-circuit 510b between the data bus line 506 a and the storage capacitance bus line526 can be repaired.

EXAMPLE 5

[0294]FIG. 48 shows a substrate surface when the interlayershort-circuit portion of the TFT substrate of the liquid crystal displaydevice is viewed from the liquid crystal layer side. In FIG. 48, twodata bus lines 506 a, 506 b and one gate bus line 502 are shown, and twopixel areas (pixel electrodes 524 a, 524 b) defined by these bus linesare shown. Also, the storage capacitance bus line 526 is shown totraverse laterally middle portions of two pixel electrodes 524 a, 524 b.

[0295] In FIG. 48, like the example 1, the data bus line 506 a isshort-circuited to the data bus line 502 at the interlayer short-circuitportion 510 a. Also, the data bus line 506 a is short-circuited to thestorage capacitance bus line 526 at the interlayer short-circuit portion510 b.

[0296] The repairing method of the interlayer short-circuit portion 510a will be explained with reference to FIG. 49 hereunder. FIG. 49 shows asectional shape of the TFT taken along an I-I′ line in FIG. 48. In thisexample 5, contact holes are opened previously in the insulating film onthe data bus lines 506 a, 506 b at a predetermined interval. Then, sparepads 568 a, 568 b, . . . made of the transparent electrode film (ITO)and connected to the data bus lines 506 a, 506 b via the contact holesare formed at the same time when the pixel electrode 524 is formed. Thespare pad 568 is formed near the intersecting portion between the databus line 506 and the gate bus line 502 and the storage capacitance busline 526.

[0297] Accordingly, the detouring circuit reaching the spare pad 568 bfrom the spare pad 568 a via the metal wiring 572 is constructed merelyby cutting off the data bus line 506 a at the disconnected portions 512a, 512 b and then connecting end portions of the spare pads 568 a, 568 bvia the metal wiring 572 formed by the laser CVD method, and thus theinterlayer short-circuit 510 a between the data bus line 506 a and thedata bus line 502 can be repaired. According to this example 5, sincethe repair can be completed merely by connecting the spare pads 568 a,568 b by the metal wiring 572 formed by the laser CVD method without theprovision of the contact holes in repairing operation, the substantialsimplification of the repairing operation can be achieved.

[0298] Similarly to the interlayer short-circuit 510 b, since the sparepads 574 a, 575 b are connected via the metal wiring 578 formed by thelaser CVD method, the interlayer short-circuit 510 b between the databus line 506 a and the storage capacitance bus line 526 can be repaired.

EXAMPLE 6

[0299]FIG. 50 shows a substrate surface when the interlayershort-circuit portion of the TFT substrate of the liquid crystal displaydevice is viewed from the liquid crystal layer side. In FIG. 50, twodata bus lines 506 a, 506 b and one gate bus line 502 are shown, and twopixel areas (pixel electrodes 524 a, 524 b) defined by these bus linesare shown. Also, the storage capacitance bus line 526 is shown totraverse laterally middle portions of two pixel electrodes 524 a, 524 b.

[0300] In FIG. 50, the data bus line 506 a is short-circuited to thedata bus line 502 at the interlayer short-circuit portion 510 a. Also,the data bus line 506 a is short-circuited to the storage capacitancebus line 526 at the interlayer short-circuit portion 510 b.

[0301] In this case, in the example 6, the interlayer short-circuit isrepaired by forming the detour route via the pixel electrode incompliance with procedures shown in FIG. 51, FIG. 52 and FIG. 53hereunder. FIG. 51 shows a sectional shape of the TFT taken along a J-J′line in FIG. 50. FIG. 52 shows a sectional shape of the TFT taken alonga K-K′ line in FIG. 50. FIG. 53 shows a sectional shape of the TFT takenalong an L-L′ line in FIG. 50.

[0302] First, the repairing method of the interlayer short-circuit 510 awill be explained with reference to FIG. 50 to FIG. 52 hereunder. Thedata bus line 506 a is disconnected at the disconnected portions 512 a,512 b, and then a contact hole 600 is formed by irradiating the laserbeam onto the outside of the disconnected portion 512 b. Then, a contacthole 592 is provided on the drain electrode 590 of the TFT that isextended from the data bus line 506 a and positioned on the gate busline 502.

[0303] Then, a metal wiring 598 is formed by the laser CVD method toconnect the contact hole 596, that is formed to connect the sourceelectrode 594 of the TFT and the pixel electrode 524 a, and the contacthole 592 formed to repair. Then, a metal wiring 602 to connect thecontact hole 600 and the left side end of the pixel electrode 524 a isformed by the laser CVD method.

[0304] Accordingly, the detouring route reaching the other disconnectedportion side of the data bus line 506 a from one disconnected portionside of the data bus line 506 a via the contact hole 592, the metalwiring 598, the contact hole 596, the pixel electrode 524 a, the metalwiring 602, and the contact hole 600 is constructed, and thus theinterlayer short-circuit 510 a between the data bus line 506 a and thedata bus line 502 can be repaired.

[0305] Then, the repairing method of the interlayer short-circuit 510 bwill be explained with reference to FIG. 50 and FIG. 53 hereunder. Thedata bus line 506 a is disconnected at the disconnected portions 512 c,512 d, and then contact holes 604, 608 are formed by irradiating thelaser beam onto the insulating film in vicinity of both disconnectedportions 512 a, 512 b respectively. Then, metal wirings 606, 700 forconnecting the contact holes 604, 608 and the pixel electrode 524 b areformed by the laser CVD method respectively.

[0306] Accordingly, the detouring route reaching the other disconnectedportion side of the data bus line 506 b from one disconnected portionside of the data bus line 506 b via the contact hole 604, the metalwiring 606, the pixel electrode 524 b, the metal wiring 700, and thecontact hole 608 is constructed, and thus the interlayer short-circuit510 b between the data bus line 506 b and the storage capacitance busline 526 can be repaired.

[0307] In the above first and second embodiments, the laser CVD methodis applied as the method of forming the conductive film in thepredetermined area to repair the fault, but the present invention is notlimited to this method. For example, it is a matter of course that theconductive film may be formed by baking the chemicals.

[0308] (Third Embodiment)

[0309]FIG. 54 is a view showing the principle of the invention set forthin claims 11 to 15 in the present invention.

[0310] In the present invention, a repairing auxiliary wiring 612 thatis independent from the gate bus line 610 is arranged adjacent to thegate bus line 610. The repairing auxiliary wiring 612 is positioned suchthat it intersects orthogonally with a storage capacitance bus linegeneral electrode 616, like the gate bus line 610, but both ends of therepairing auxiliary wiring 612 do not overlap with the storagecapacitance bus line general electrode 616. In addition, repairingconnection electrodes 614 a, 614 b are provided on both sides of thestorage capacitance bus line general electrode 616 to intersectorthogonally with the gate bus line 610 and the repairing auxiliarywiring 612.

[0311]FIG. 55 is a view showing the short-circuit fault repairingmethod.

[0312] The gate bus line 610 and the storage capacitance bus linegeneral electrode 616 are short-circuited at a point P. In such case,first two points R1, R2 located on both sides of the storage capacitancebus line general electrode 616 are disconnected by the laser beamirradiation, etc. to separate the short-circuited portion from the gatebus line 610. Then, the gate bus line 610 and the repairing auxiliarywiring 612 are connected mutually by the laser beam irradiation, etc. atfour points Q1 to Q4 at which the gate bus line 610 and the repairingauxiliary wiring 612 intersect orthogonally with each other. In thismanner, the fault is repaired.

[0313]FIG. 56 is a sectional view taken along a I-I line in FIG. 55.

[0314] The gate bus line 610 and the repairing auxiliary wiring 612 areformed independently on the insulating substrate 618. The gate bus line610 and the repairing auxiliary wiring 612 are formed simultaneously bypatterning the same conductive film. Also, the storage capacitance busline is formed by the same steps. A repairing connection electrode 614 b(614 a) is formed on the gate bus line 610 and the repairing auxiliarywiring 612 via an insulating film (gate insulating film) 620. Therepairing connection electrode 614 b (614 a) is formed simultaneously bythe same material in the steps applied to form the drain electrode ofthe TFT and the data bus line. The storage capacitance bus line generalelectrode 616 is formed by the same steps as the data bus line. Uponrepairing the fault, the gate bus line 610 and the repairing auxiliarywiring 612 are connected electrically by applying the laser beamirradiation, etc. to the portions (points Q3, Q4), at which therepairing connection electrode 614 b (614 a) and the gate bus line 610and the repairing auxiliary wiring 612 intersect orthogonally mutually,to melt the repairing connection electrode 614 b.

[0315] As the method of connecting the repairing connection electrode614 b and the gate bus line 610 and the repairing auxiliary wiring 612,there may be used the so-called laser CVD method, in which the metalfilm is formed selectively on the substrate surface by irradiating thelaser beam to the atmosphere containing the metal, in addition to theabove melting of the conductive layer by the laser beam irradiation.Also, since the conductive film can be formed at any position if thislaser CVD method is employed, there is no necessity to form previouslythe repairing connection electrode 614 b.

[0316] More particularly, in FIG. 55 and FIG. 56 (assuming repairwirings that the repairing connection electrode 614 a and 614 b are notprovided), if the gate bus line 610 and the storage capacitance bus linegeneral electrode 616 are short-circuited at the point P, the gate busline 610 is disconnected at two points R1, R2 located on both sides ofthe storage capacitance bus line general electrode 616. Then, theinsulating film 620 formed on the gate bus line 610 and the repairingauxiliary wiring 612 is removed at four points Q1 to Q4 to expose thegate bus line 610 and the repairing auxiliary wiring 612. Then, theconductive films for connecting the points Q1 and Q2 and the points Q3and Q4 are formed by the laser CVD method. In this way, the fault can berepaired.

[0317]FIG. 57 is a view showing a short-circuit repairing method for theliquid crystal display device according to the third embodiment of thepresent invention.

[0318] In the liquid crystal display device of the present invention,the gate bus lines are extracted only to the left side, like FIG. 1, andthus the gate bus lines and the storage capacitance bus line generalelectrode intersect mutually only on the left end portion. FIG. 57 showsthe area in which the gate bus line 610 and the storage capacitance busline general electrode 616 intersect mutually. Since the storagecapacitance bus line general electrode 616 is formed in the same layeras the data bus line 634 and formed by the same material by the samesteps, it is arranged to extend in parallel with the data bus line 634and intersect with the gate bus line 610. The difference of the examplein FIG. 57 from the conventional configuration in FIG. 2 resides in thatthe repairing auxiliary wiring 612 and the repairing connectionelectrode 614 a and 614 b are provided near the intersecting portionbetween the gate bus line 610 and the storage capacitance bus linegeneral electrode 616.

[0319]FIG. 58 is a partially enlarged view showing a part of the liquidcrystal display device in FIG. 57. Bending portions 610 a, 610 b (seeFIG. 57) are provided to the gate bus line 610, and such bendingportions 610 a, 610 b are formed wider than the normal wiring width. Thegate bus line 610 is overlapped with the repairing connection electrode614 a, 614 b at the bending portions 610 a, 610 b (see FIG. 57). In thiscase, the insulating film is present between the bending portions 610 a,610 b and the repairing connection electrodes 614 a, 614 b. The reasonfor that the width of the overlapped portion is extended is to take intoconsideration the event that a part of the gate bus line 610 disappearsdue to the laser process described later. Also, the repairing auxiliarywiring 612 is provided close to but electrically independently to thegate bus line 610. The repairing auxiliary wiring 612 is formed to havethe substantially same wiring width as the gate bus line 610. A top endportion of the repairing auxiliary wiring 612 is extended in width likethe bending portion 610 a of the gate bus line 610 and is overlappedwith the repairing connection electrodes 614 a, 614 b.

[0320] According to such configuration, it is feasible to check thepresence of the short-circuit by performing the electrical test. Inaddition, since the repairing auxiliary wiring 612 and the gate bus line610 are provided independently prior to the repairing process and notelectrically connected mutually, the disconnected portion to beseparated or the portion to be electrically connected can be decided ifthe short-circuited gate bus line 610 can be identified. Thus, arepairing rate can be improved.

[0321] Storage capacitance bus lines 622 and the storage capacitance busline general electrode 616 are connected via storage capacitance busline connecting electrodes 624, that are formed by the same steps as thepixel electrode, via the connection portions 624 a, 624 b.

[0322]FIG. 59 is a view showing the connected portion between thestorage capacitance bus lines 622 and the storage capacitance bus linegeneral electrode 616, and a sectional view taken along a II-II line inFIG. 58.

[0323] The storage capacitance bus lines 622 that are formed by the samesteps as the gate bus line 610 to constitute the storage capacitancestogether with the pixel electrodes 632 respectively are provided on theinsulating substrate 618. The storage capacitance bus line generalelectrode 616 is formed by the same steps as the data bus lines 634 andprovided on the gate insulating film 620. The storage capacitance busline connecting electrodes 624 are formed by the same steps as the pixelelectrodes 632 to connect electrically the storage capacitance bus lines622 and the storage capacitance bus line general electrode 616 viaconnection portions 624 a, that are provided by opening the gateinsulating film 620 and the protection film 636 on the storagecapacitance bus lines 622, and connection portions 624 b, that areprovided by opening the protection film 636 on the storage capacitancebus line general electrode 616. In order to improve the adhesiveness ofthe storage capacitance bus line connecting electrodes 624, connectionportions 624 c are provided to come into contact with the insulatingsubstrate 618.

[0324] (Fourth Embodiment)

[0325]FIG. 60 is a plan view showing the TFT substrate of the liquidcrystal display device according to a fourth embodiment of the presentinvention. Since the CF substrate is basically identical to the CFsubstrate in the prior art, explanation of the CF substrate will beomitted herein.

[0326] As shown in FIG. 60, spare TFTs 717 in addition to TFTs 716serving as the switching element are provided to the TFT substrate ofthe liquid crystal display device according to the fourth embodiment.

[0327] More particularly, a plurality of gate bus lines 712 and aplurality of storage capacitance bus lines 713 are formed as the firstwiring layer on a glass substrate 711. Respective gate bus lines 712 areformed in parallel mutually, and the storage capacitance bus lines 713are arranged in parallel with the gate bus lines 712 between the gatebus lines 712 respectively. This first wiring layer is formed of Cr(chromium), for example.

[0328] The gate bus lines 712 and the storage capacitance bus lines 713are covered with a first insulating film (gate insulating film; notshown) formed of silicon oxide. Silicon films (amorphous silicon film orpolysilicon film) 714 a, 714 b serving as the channels of the TFTs 716,717 are formed on the first insulating film. Also, a plurality of databus lines 715, source electrodes 716 s and drain electrodes 716 d of theTFTs 716, and source electrodes 717 s and drain electrodes 717 d of thespare TFTs 717 are formed as the second wiring layer on the firstinsulating film. This second wiring layer has a triple-layered structurethat is formed of Ti (titanium)/Al (aluminum)/Ti (titanium), forexample.

[0329] The data bus lines 715 are formed to intersect orthogonally withthe gate bus lines 712. The source electrodes 716 s and the drainelectrodes 716 d are formed on both sides of the silicon films 714 a inthe width direction to be separated mutually. The source electrodes 717s and the drain electrodes 717 d are formed on both sides of the siliconfilms 714 b in the width direction to be separated mutually. Rectangularareas partitioned by the gate bus lines 712 and the data bus lines 715are the pixel areas respectively.

[0330] The data bus lines 715, the TFTs 716, and the TFTs 717 arecovered with a second insulating film (protection insulating film; notshown) formed of silicon oxide. Pixel electrodes 719 made of ITO areformed on the second insulating film.

[0331] As shown in FIG. 60, the source electrodes 716 s of the TFTs 716are connected to the data bus lines 715, and source electrode terminals716 b are connected to the pixel electrodes 719 via the contact holes718 a formed in the protection insulating film.

[0332] Meanwhile, the drain electrode terminals 717 a and the sourceelectrode terminals 717 b of the spare TFTs 717 are connected tonowhere. This is because, if the spare TFTs 717 are connected to thedata bus lines 715 and the pixel electrodes 719, large load capacitances(Cgs) are generated between the gate bus lines 712 and the data bus line715 and the pixel electrodes 719 to cause the degradation of the displayquality. In this case, in the fourth embodiment, the source electrodeterminals 717 b are formed at positions that overlap partially with thepixel electrodes 719.

[0333] The fault repairing method for the liquid crystal display panelaccording to the fourth embodiment of the present invention will beexplained with reference to FIG. 61 and FIGS. 62A to 62C hereunder. Inthis fourth embodiment, as shown in FIG. 61, the fault repairing methodapplied to the case where the source electrodes 716 s and the drainelectrodes 716 d of the TFTs 716 are short-circuited by a foreign matter729 will be explained.

[0334]FIGS. 62A to 62C are schematic sectional views showing the faultrepairing method in the order of steps. In FIGS. 62A to 62C, a symbol722 denotes the first insulating film (gate insulating film), and asymbol 723 denotes the second insulating film (protection insulatingfilm).

[0335] First, the pixel electrode 719 and the data bus line 715 areelectrically separated mutually. For example, the drain electrode 716 dis disconnected at a portion indicated by a dot-dash line in FIG. 61 byirradiating the pulse laser beam, for example.

[0336] Then, the contact holes 718 b, 718 c are formed on the drainelectrode 716 d (the portion connected to the data bus line 715) of theTFT 716 and the drain electrode terminal 717 a of the spare TFT 717.More particularly, as shown in FIG. 62A, the laser pulse is irradiatedto the second insulating film 723 on the drain electrode 716 d and theterminal 717 a and thus, as shown in FIG. 62B, the contact holes 718 b,718 c are formed. Since this laser beam irradiation intends not to meltthe drain electrode 716 d and the terminal 717 a but form the contacthole in the second insulating film 723, the short-wavelength laser beamis employed. For example, if the third harmonic (wavelength 355 nm) orthe fourth harmonic (wavelength 266 nm) of the YAG laser is employed,the contact holes 718 b, 718 c can be formed in the second insulatingfilm 723 without the melting of the drain electrode 716 d and theterminal 717 a.

[0337] Then, as shown in FIG. 62C, a conductive pattern (wiring) 721that connects electrically the drain electrode 716 d and the terminal717 a is formed by the laser CVD method. According to the laser CVD, theconductive pattern 721 is formed by continuously irradiating the YAGlaser beam whose wavelength is 355 nm, while flowing locally the Ar(argon) gas containing W (tungsten) organic metal, Mo (molybdenum)organic metal, or Cr (chromium) organic metal around the conductivepattern forming area. At this time, the concentration of the organicmetal gas, the laser power, the scanning rate, and the number of timesof scanning are adjusted appropriately. For example, as the conductivepattern 721 forming condition parameters for the laser CVD, the scanningrate is 3.0 μm/sec, the laser transmittance rate is 55%, the laser Qswitching frequency is 4 kHz, the flow rate of the carrier gas is 90cc/min, the temperature of the material gas is 53° C., and the slit sizeof the film forming area is 5 μm×5 μm. When the inventors of thisapplication formed actually the conductive pattern formed of tungsten,the conductive pattern in which the minimum drawing line width was 5 μm,the film thickness was 30 nm, and the specific resistance was less than50 μΩcm could be formed.

[0338] In contrast, the source electrode 717 s of the spare TFT 717 isconnected electrically to the pixel electrode 719. That is, the contacthole 718 d in the second insulating film 723 is formed by irradiatingthe YAG laser beam, for example, to the overlapped areas of the sourceelectrode terminal 717 b and the pixel electrode 719, and also the pixelelectrode 719 and the source electrode 717 s are connected electricallyby melt-jointing (laser welding) the pixel electrode 719 in theconcerned area and the source electrode 717 s.

[0339] Accordingly, the fault repair of the liquid crystal panel can becompleted.

[0340] According to the fault repairing method for the liquid crystaldisplay device of the fourth embodiment, since the conductive patternfor connecting the drain electrode 717 d of the spare TFT 717 and thedata bus line 715 is formed by the laser CVD method and then the sourceelectrode 717 s of the spare TFT 717 and the pixel electrode 719 areconnected by the melt-joint using the laser, the defective pixel can berestored into the normal pixel. That is, according to the fourthembodiment, since the fault is not made inconspicuous but the defectivepixel is restored into the normal pixel by repairing the fault, the highquality pixel display can be achieved and also the yield of fabricationof the liquid crystal display panel can be improved.

[0341] According to the liquid crystal display device of the fourthembodiment, since the source electrode 717 s and the drain electrodes717 d of the spare TFT 717 are not connected to the pixel electrodes 719and the data bus lines 715, the increase of the load capacitance can beavoided.

[0342] In the fourth embodiment, the case where the fault caused by theshort-circuit between the source electrode 716 s and the drainelectrodes 716 d of the TFT 716 is repaired is explained. But thepresent invention can be applied to the fault repair caused by the ONcharacteristic failure of the TFT 716. That is, if the writing abilitylacks because of the insufficient ON characteristic of the TFT 716, thesource electrode 717 s is connected to the pixel electrode 719 byconnecting the drain electrodes 717 d of the spare TFT 717 to the databus line 715, without the disconnection of the drain electrode 716 d ofthe TFT 716, like the above embodiment. As a result, two TFTs 716, 717are connected in parallel to increase the writing ability and thus thereduction in display quality due to the ON characteristic failure of theTFT 716 can be avoided.

[0343] In addition, in the fourth embodiment, the conductive pattern 721is formed after the drain electrode 716 d is separated. But the drainelectrode 716 d may be disconnected after the conductive pattern 721 isformed.

[0344] Furthermore, in the fourth embodiment, the case where one spareTFT is provided is explained. Two spare TFTs or more may be provided.

[0345] (Fifth Embodiment)

[0346] A fifth embodiment of the present invention will be explainedwith reference to FIGS. 63A to 63C hereunder. Since the fifth embodimentis basically similar to the fourth embodiment except that the conductivepattern forming method is different, their detailed explanation will beomitted by affixing the same symbols to the same constituent elements inFIGS. 63A to 63C as those in FIG. 62.

[0347] In the fourth embodiment, the conductive pattern 721 is formed bythe laser CVD method. In contrast, in the fifth embodiment, theconductive pattern 721 is formed by baking the conductive paste(conductive chemicals).

[0348] More particularly, as shown in FIG. 63A, like the fourthembodiment, contact holes 718 b, 718 c are formed on the drain electrode716 d of the TFT 716 and the drain electrode terminal 717 a of the spareTFT 717 respectively.

[0349] Then, as shown in FIG. 63B, conductive paste 724 containing Au(gold), Ag (silver), or the like is coated on the area containing thecontact holes 718 b, 718 c. Then, the conductive paste 724 is baked byirradiating the laser beam to the area containing the contact holes 718b, 718 c.

[0350] Then, the conductive paste 724 is removed from the unbaked area.As a result, as shown in FIG. 63C, the conductive pattern 721 forconnecting the drain electrode 716 d of the TFT 716 and the drainelectrode terminal 717 a of the spare TFT 717 can be completed.

[0351] In the fifth embodiment, like the fourth embodiment, the liquidcrystal display panel having no defective pixel can be obtained byrepairing the fault of the liquid crystal display panel.

[0352] (Sixth Embodiment)

[0353] A sixth embodiment of the present invention will be explainedwith reference to FIG. 64 hereunder. Since the fifth embodiment isbasically similar to the fourth embodiment except that the conductivepattern forming method is different, their detailed explanation will beomitted by affixing the same symbols to the same constituent elements inFIG. 64 as those in FIG. 62.

[0354] In the sixth embodiment, when the contact hole 718 a is formed inthe second insulating film after the second insulating film (protectioninsulating film) is formed, the contact hole reaching the drainelectrode 716 d of the TFT 716 and the contact hole reaching the drainelectrode terminal 717 a of the spare TFT 717 are formed simultaneously.

[0355] Then, the ITO film is formed on the overall surface. Then, thepixel electrodes 719 are formed by patterning the ITO film and also pads719 a connected to the drain electrodes 716 d of the TFTs 716 and pads719 b connected to the drain electrode terminals 717 a of the spare TFTs717 are formed.

[0356] If the short-circuit between the source electrode 716 s and thedrain electrode 716 d of the TFT 716 occurs due to the foreign matter,as shown in FIG. 65, for example, on the TFT substrate constructed inthis way, the conductive pattern 721 for connecting the pads 719 a, 719b is formed in the same manner as the fourth embodiment or the fifthembodiment. Then, the drain electrode 716 d is disconnected at aposition indicated by a dot-dash line in FIG. 65, for example.

[0357] In this case, if the short-circuit between the source electrode716 s and the drain electrode 716 d of the TFT 716 does not occur butthe ON characteristic failure of the TFT 716 is caused, there is nonecessity to disconnect the drain electrode 716 d.

[0358] According to the sixth embodiment, in addition to the advantagesobtained in the fourth embodiment, there is such an advantage that thereis no need to form the contact hole in the second insulating film byirradiating the laser beam in repairing the fault. Also, since the pads719 a, 719 b are formed simultaneously with the pixel electrodes 719,the increase in the number of steps can be avoided.

[0359] (Seventh Embodiment)

[0360]FIG. 66 is a view showing the TFT substrate of the liquid crystaldisplay device according to a seventh embodiment of the presentinvention. In FIG. 66, the same symbols are affixed to the sameconstituent elements as those in FIG. 60 and their detailed explanationwill be omitted. Also, in the seventh embodiment, since theconfiguration of the CF substrate is basically similar to that in theprior art, the explanation of the CF substrate will be omitted.

[0361] On the TFT substrate of the liquid crystal display deviceaccording to the seventh embodiment, a spare TFT 731 is provided everypixel in addition to the TFT 716 serving as the switching element.

[0362] This spare TFT 731 consists of a gate electrode 731 g formed inthe first wiring layer in which the gate bus line 712 and the storagecapacitance bus line 713 are formed, a silicon film 714 c formed on thegate electrode 731 g via the first insulating film, and the data busline 715 and a source electrode 731 s arranged on both sides of thesilicon film 714 c in the width direction. The source electrode 731 s isarranged in the second wiring layer like the data bus line 715. Thesource electrode 731 s is connected to nowhere. In this case, a sourceelectrode terminal 731 a overlaps with a part of the pixel electrode 719to put the protection insulating film between them. Also, the portion ofthe data bus line 715 that overlaps with the silicon film 714 c acts asthe drain electrode of the TFT 731.

[0363] The fault repairing method for the liquid crystal display panelaccording to the seventh embodiment will be explained with reference toFIG. 67 and FIG. 68 hereunder. FIG. 68 is a sectional view taken along aIII-III line in FIG. 67. In this seventh embodiment, as shown in FIG.67, the fault repair applied when the short-circuit between the drainelectrode 716 d and the source electrode 716 s of the TFT 716 occurs dueto the foreign matter 729 will be explained hereunder.

[0364] First, the pixel electrode 719 and the data bus line 715 aredisconnected electrically. The connecting portion (portion indicated bya dot-dash line in FIG. 67) between the drain electrode 716 d and thedata bus line 715 is cut off by irradiating the pulse laser beam, forexample.

[0365] Then, contact holes 718 g, 718 f are formed on the gate electrode731 g and the gate bus line 712. As explained in the fourth embodiment,the third harmonic or the fourth harmonic of the YAG laser is employedto form the contact holes 718 g, 718 f.

[0366] Then, the conductive pattern for connecting electrically the gateelectrode 731 g and the gate bus line 712 is formed by the laser CVDmethod. According to the laser CVD, the conductive pattern 732 is formedby continuously irradiating the YAG laser beam whose wavelength is 355nm, while flowing the Ar (argon) gas containing W (tungsten) organicmetal, Mo (molybdenum) organic metal, or Cr (chromium) organic metal.

[0367] Then, the source electrode 731 s of the spare TFT 731 and thepixel electrode 719 are connected electrically. That is, the contacthole 718 e is formed in the second insulating film 723 by irradiatingthe YAG laser beam, for example, to the overlapped areas of the sourceelectrode terminal 731 a and the pixel electrode 719, and also the pixelelectrode 719 and the source electrode 731 s are connected electricallyby melt-jointing (laser welding) the pixel electrode 719 in theconcerned area and the source electrode 717 s. Accordingly, the faultrepair of the liquid crystal panel can be completed.

[0368] In the seventh embodiment, in the case of the ON characteristicfailure of the TFT 716, there is no need to disconnect the TFT 716 andthe data bus line 715. Also, like the fifth embodiment, the conductivepattern 732 may be formed by baking the conductive paste. In addition,like the sixth embodiment, the pads may be formed previously at thepositions that correspond to the contact holes 718 f, 718 g. As aresult, there are omitted the steps of forming the contact holes inrepairing the fault.

[0369] Besides, in the above fourth to seventh embodiment, the faultrepair of the liquid crystal display device in which the protectioninsulating film is formed on the TFTs is explained. But the presentinvention may be applied to the liquid crystal display device in whichthe protection insulating film is not formed. In this case, the steps offorming the contact holes can be omitted.

[0370] (Eighth Embodiment)

[0371]FIG. 69 is a schematic view showing a TFT substrate of a liquidcrystal display device according to an eighth embodiment of the presentinvention. In the eighth embodiment, since the configuration of the CFsubstrate is basically similar to that in the prior art, the explanationof the CF substrate will be omitted.

[0372] A plurality of gate bus lines 812 and a plurality of data buslines 815 are formed in a display area 800 a of a TFT substrate 800. Therectangular areas partitioned by the gate bus lines 812 and the data buslines 815 are the pixels respectively. Although the TFT, the pixelelectrode, and the auxiliary capacitance are formed in the pixelrespectively, their illustration is omitted in FIG. 69.

[0373] TAB terminals 822 and spare TAB terminals 821 are aligned alongone side (referred to as a “first side” hereinafter) of the TFTsubstrate 800. The TAB terminals 822 are divided into a plurality ofgroups, and the spare TAB terminals 821 are arranged such that two spareTAB terminals 821 are assigned to each group to put the group betweenthem. Each spare TAB terminal 821 is connected to the corresponding databus line 815. The video signals are supplied to these TAB terminals 822via the TAB substrate (see FIG. 1).

[0374] An alignment pitch of the TAB terminals 822 is set smaller thanan alignment pitch of the data bus lines 815. Also, a repair terminal822 a is provided to each data bus line 815 in vicinity of the TABterminal 822, and a repair terminal 822 b is provided to the other endside. While, the spare TAB terminals 821 are connected to the repairterminals 821 a that are arranged in vicinity of the spare TAB terminals821 respectively.

[0375] One or a plurality (two in FIG. 69) of repair wirings 824 areformed near the side of the TFT substrate 800 opposing to the first side(referred to as a “second side” hereinafter) in parallel with the secondside.

[0376] Also, TAB terminals 831 and spare TAB terminals 823 are alignedalong other one side (referred to as a “first side” hereinafter)adjacent to the first side of the TFT substrate 800. Each TAB terminal831 is connected to the corresponding gate bus line 812. Also, eachspare TAB terminal 823 is connected to the repair wiring 824. Thescanning signals are supplied to these TAB terminals 831 via the TABsubstrate (see FIG. 1).

[0377] As shown in FIG. 69, all the TAB terminals 822, 831, the spareTAB terminals 821, 823, the repair terminals 822 a, 822 b, and therepair wiring 824 are provided on the outside of the display area 800 a.Also, the repair terminals 822 b of the data bus lines 815 are arrangednear the repair wiring 824.

[0378] The fault repairing method for the liquid crystal display deviceaccording to the eighth embodiment will be explained with reference toFIGS. 70A and 70B and FIGS. 71A and 71B hereunder. FIG. 71A is asectional view taken along a IV-IV line in FIG. 70A, and FIG. 71B is asectional view taken along a V-V line in FIG. 70B.

[0379] In this eighth embodiment, it is on the assumption that thedisconnection of the data bus line 815 occurs at portions indicated by a× mark in FIGS. 70A and 70B. Also, in FIGS. 71A and 71B, 802 denotes thefirst insulating film (gate insulating film) provided to the TABsubstrate 800, and 803 denotes the second insulating film (protectioninsulating film).

[0380] First, contact holes 803 a to 803 d are formed by irradiating thelaser beam onto the repair terminals 822 a, 822 b of the disconnecteddata bus line 815, the repair terminal 821 a of the spare TAB terminal821, and the repair wiring 824 respectively. According to this laserirradiation, the contact holes 803 a to 803 d can be formed in thesecond insulating film 803 by employing the short-wavelength laser beam,without the melting of the repair terminals 821 a, 822 a, 822 b and therepair wiring 824. For example, the third harmonic (wavelength 355 nm)or the fourth harmonic (wavelength 266 nm) of the YAG laser can beemployed as the laser beam.

[0381] Then, the conductive pattern 825 a for connecting electricallythe repair terminal 821 a and the repair terminal 822 a and theconductive pattern 825 b for connecting electrically the repair terminal822 b and the repair wiring 824 are formed by the laser CVD method.These conductive patterns 825 a, 825 b are formed by continuouslyirradiating the YAG laser beam whose wavelength is 355 nm, while flowinglocally the Ar (argon) gas containing W (tungsten) organic metal, Mo(molybdenum) organic metal, or Cr (chromium) organic metal around theconductive pattern forming area. At this time, the concentration of theorganic metal gas, the laser power, the scanning rate, and the number oftimes of scanning are adjusted appropriately. For example, according tothe examination made by the inventors of this application, if thescanning rate is 3.0 μm/sec, the laser transmittance rate is 65%, thelaser Q switching frequency is 4 kHz, the flow rate of the carrier gasis 89 cc/min, the temperature of the material gas is 52° C., and theslit size of the film forming area is 5 μm×5 μm, the conductive patternin which the minimum drawing line width is 5 μm, the film thickness is30 nm, and the specific resistance is less than 50 μΩcm can be formed.

[0382] Then, the spare TAB terminal 821 connected to the data bus line815 and the spare TAB terminal 823 are connected electrically via thewire. Accordingly, the fault repair of the liquid crystal display devicecan be completed.

[0383] According to the fault repairing method for the liquid crystaldisplay device of the eighth embodiment, the repair terminal 822 a andthe spare TAB terminal 821 and the repair terminal 822 b and the repairwiring 824 of the data bus line 815 which is disconnected are connectedby the conductive patterns 825 a, 825 b formed by the laser CVD methodrespectively. As a result, the line fault caused by the disconnection ofthe data bus line 815 can be repaired and thus the liquid crystaldisplay device can be restored to the normal liquid crystal displaydevice.

[0384] In the above embodiments, the data bus line 815 in which thefault occurs and the spare TAB terminal 821 are connected by theconductive pattern and the spare TAB terminal 821 and the spare TABterminal 823 are connected by the wire. However, if the TAB terminal 823and the TAB terminal 822 can be directly connected electrically, thespare TAB terminal 821 and the conductive pattern 825 a are not needed.

[0385] Also, in the eighth embodiment, the conductive patterns 825 a,825 b are formed by the laser CVD method. As explained in the fifthembodiment, the conductive pattern may be formed by baking theconductive paste.

[0386] In addition, in the eighth embodiment, the case where two repairwirings 824 are employed is explained. In this case, two disconnecteddata bus lines can be repaired. But the number of the repair wirings 824is not limited to two in the present invention, and one or three repairwirings may be employed.

[0387] Furthermore, as shown in a plan view of FIG. 72A and a side viewof FIG. 72B, if the repair terminals 821 a, 822 a, 822 b and the repairwiring 824 are arranged on the outside of the CF substrate 850, thedisconnection of the data bus line 815 can be repaired after the TFTsubstrate 800 and the CF substrate 850 are jointed together.

[0388] (Ninth Embodiment)

[0389] A ninth embodiment of the present invention will be explainedwith reference to FIGS. 73A and 73B and FIGS. 74A and 74B hereunder.Since the ninth embodiment is basically similar to the eighth embodimentexcept that the conductive pattern forming method is different, theirdetailed explanation will be omitted by affixing the same symbols to thesame constituent elements in FIGS. 73A, 73B and FIGS. 74A, 74B as thosein FIGS. 70A, 70B and FIGS. 71A, 71B. FIG. 74A is a sectional view takenalong a VI-VI line in FIG. 73A, and FIG. 74B is a sectional view takenalong a VII-VII line in FIG. 73B.

[0390] In the ninth embodiment, when the contact hole reaching thesource electrode of the TFT is formed in the second insulating film 803after the second insulating film (protection insulating film) 803 isformed, the contact hole reaching the repair terminals 821 a, 822 a, 822b and the contact hole reaching the repair wiring 824 are formedsimultaneously. The contact holes are formed in the repair wiring 824 atpositions that correspond to the repair terminals 822 b respectively.

[0391] Then, the ITO film is formed on the overall surface. Then, thepixel electrodes 719 are formed by patterning the ITO film and also pads819 a connected to the repair terminals 821 a, pads 819 b connected tothe repair terminals 821 a, pads 819 c connected to the repair terminals822 b, and pads 819 d connected to the repair wirings 824 are formed.

[0392] If the disconnection of the data bus line 815 is caused at aposition indicated by a × mark, as shown in FIGS. 73A and 73B, forexample, on the TFT substrate constructed in this manner, the conductivepattern 825 c for connecting the pad 819 a and the pad 819 b and theconductive pattern 825 d for connecting the pad 819 c and the pad 819 dare formed by the laser CVD method or by baking the conductive paste.

[0393] According to the ninth embodiment, in addition to the advantagesobtained in the eighth embodiment, there is such an advantage that thereis no need to form the contact hole in the second insulating film 803 byirradiating the laser beam upon repairing the fault. Also, since thepads 819 a to 819 d are formed simultaneously with the pixel electrodes,the increase in the number of steps can be avoided.

[0394] In the eighth and ninth embodiment, the case where thedisconnection of the data bus line is repaired is explained. But thepresent invention can be applied to the repair of the disconnection ofthe gate bus line.

What is claimed is:
 1. A fault repairing method for a liquid crystaldisplay device, comprising the steps of: forming first and seconddisconnection repairing contact holes, that have a width larger than awidth of a disconnected wiring and a depth to expose an upper surfaceand both side surfaces of the disconnected wiring respectively, at twolocations which are positioned to sandwich a disconnected portion of thedisconnected wiring; and forming first and second conductive films, thatare connected electrically to the upper surface and both side surfaces,on inner walls and surfaces of the first and second disconnectionrepairing contact holes to repair the disconnection.
 2. The faultrepairing method for a liquid crystal display device according to claim1 , wherein the first and second conductive films are formed by a laserCVD method.
 3. A fault repairing method for a liquid crystal displaydevice, comprising the steps of: forming first and second disconnectionrepairing contact holes, that have a width larger than a width of adisconnected wiring and a depth to expose an upper surface and both sidesurfaces of the disconnected wiring respectively, at two locations whichare positioned to sandwich a disconnected portion of the disconnectedwiring; and forming a conductive film, that is connected electrically tothe upper surface and both side surfaces, on inner walls and surfaces ofthe first and second disconnection repairing contact holes to repair thedisconnection.
 4. The fault repairing method for a liquid crystaldisplay device according to claim 3 , wherein the conductive film isformed by a laser CVD method.
 5. The fault repairing method for a liquidcrystal display device according to claim 1 , wherein both the first andsecond conductive films are connected to a pixel electrode.
 6. A faultrepairing method for a liquid crystal display device comprising thesteps of: forming a conductive film over an area located betweendisconnection end portions of a disconnected wiring by a laser CVDmethod; and connecting electrically the conductive film and thedisconnection end portions by a laser welding method to repair thedisconnection.
 7. A liquid crystal display device in which a liquidcrystal is sealed between a first substrate, on which first and secondwirings intersected via an insulating film are formed, and a secondsubstrate that opposes to the first substrate, comprising: spare wiringsthat are formed in vicinity of intersecting positions of the first andsecond wirings and constitute a part of a detour route used when aninterlayer short-circuit between the first and second wirings isrepaired.
 8. A liquid crystal display device in which a liquid crystalis sealed between a first substrate, on which first and second wiringsintersected via an insulating film are formed, and a second substratethat opposes to the first substrate, comprising: spare pads that areconnected to any one of the first and second wirings in vicinity ofintersecting positions of the first and second wirings and constitute apart of a detour route used when an interlayer short-circuit between thefirst and second wirings is repaired.
 9. A fault repairing method for aliquid crystal display device comprising the steps of: disconnecting onewiring of first and second wirings in which an interlayer short-circuitoccurs, at two locations that sandwich a short-circuit portion toseparate electrically from other wiring; and forming a detour route todetouring the short-circuit portion to connect electricallydisconnection end portions of one wiring.
 10. The fault repairing methodfor a liquid crystal display device according to claim 9 , wherein thedetour route contains spare wirings, that are formed in vicinity of anintersecting position of the first and second wirings to repair aninterlayer short-circuit between the first and second wirings, as a partof its configuration.
 11. The fault repairing method for a liquidcrystal display device according to claim 9 , wherein the detour routecontains spare pads, that are connected to any one of the first andsecond wirings in vicinity of an intersecting position of the first andsecond wirings to repair an interlayer short-circuit between the firstand second wirings, as a part of its configuration.
 12. A liquid crystaldisplay device comprising: a plurality of gate bus lines; a plurality ofstorage capacitance bus lines; a storage capacitance bus line generalelectrode connected commonly to the storage capacitance bus lines, andarranged to intersect with the plurality of gate bus lines to sandwichan insulating film; repairing auxiliary wirings that are intersectedwith the storage capacitance bus line general electrode and are providedelectrically independently from the gate bus lines; and repairingconnecting electrodes arranged on both sides of the storage capacitancebus lines general electrode in a width direction respectively, one endsof which overlap with the gate bus lines and other ends of which overlapwith the repairing auxiliary wirings.
 13. The liquid crystal displaydevice according to claim 12 , wherein the repairing auxiliary wiringsare formed by same steps as the gate bus lines.
 14. The liquid crystaldisplay device according to claim 12 , wherein the repairing connectingelectrodes are formed by same steps as the storage capacitance bus linegeneral electrode.
 15. A fault repairing method of repairing ashort-circuit between a gate bus line and a storage capacitance bus linegeneral electrode in a liquid crystal display device that includes aplurality of gate bus lines, a plurality of storage capacitance buslines, and a storage capacitance bus line general electrode that isconnected commonly to the plurality of storage capacitance bus lines andintersected with the gate bus lines to sandwich an insulating filmbetween them, comprising the steps of: forming repairing auxiliarywirings to intersect with the storage capacitance bus line generalelectrode; forming repairing connection electrodes one ends of which areconnected to the gate bus lines and other ends of which are connected tothe repairing auxiliary wirings; and disconnecting a gate bus line, thatis short-circuited to a storage capacitance bus line general electrode,on both sides of the storage capacitance bus line general electrode. 16.A fault repairing method of repairing a short-circuit between a gate busline and a storage capacitance bus line general electrode in a liquidcrystal display device that includes a plurality of gate bus lines, aplurality of storage capacitance bus lines, and a storage capacitancebus line general electrode that is connected commonly to the pluralityof storage capacitance bus lines and intersected with the gate buslines, comprising the steps of: forming repairing auxiliary wirings tointersect with the storage capacitance bus line general electrode;disconnecting a gate bus line, that is short-circuited to a storagecapacitance bus line, on both sides of the storage capacitance bus linegeneral electrode; exposing two locations of the gate bus line tosandwich the storage capacitance bus line general electrode betweenthem; exposing two locations of the repairing auxiliary wiring tosandwich the storage capacitance bus line general electrode; anddepositing a conductive film on an area extended from an exposed portionof the gate bus line to an exposed portion of the repairing auxiliarywiring to connect electrically the gate bus line to the repairingauxiliary wiring.
 17. A fault repairing method for a liquid crystaldisplay device that includes switching thin film transistors that areconnected to gate bus lines, data bus lines and pixel electrodes, andspare thin film transistors that are not connected to the data buslines, comprising the step of: forming a conductive pattern, thatconnects a drain electrode of a spare thin film transistor and a databus line, in repairing a fault.
 18. The fault repairing method for aliquid crystal display device according to claim 17 , wherein theconductive pattern is formed by a laser CVD method or by bakingconductive chemicals by virtue of a laser beam irradiation.
 19. Thefault repairing method for a liquid crystal display device according toclaim 17 , wherein the spare thin film transistor is separated from thepixel electrode, a source electrode of the spare thin film transistorand the pixel electrode are connected by a laser welding in repairingthe fault.
 20. The fault repairing method for a liquid crystal displaydevice according to claim 17 , wherein contact holes are opened in aninsulating film on the drain electrode of a spare thin film transistorand on a drain electrode of a switching thin film transistor, by laserbeam irradiation before forming the conductive pattern.
 21. The faultrepairing method for a liquid crystal display device according to claim17 , wherein the conductive pattern is formed of any one metal selectedfrom a group consisting of tungsten, molybdenum, chromium, gold, andsilver.
 22. A fault repairing method for a liquid crystal display devicethat includes switching thin film transistors that are connected to gatebus lines, data bus lines and pixel electrodes, and spare thin filmtransistors that are not connected to the gate bus lines, comprising thestep of: forming a conductive pattern, that connects at least a gateelectrode of a spare thin film transistor and a gate bus line, inrepairing a fault.
 23. The fault repairing method for a liquid crystaldisplay device according to claim 22 , wherein the conductive pattern isformed by a laser CVD method or by baking conductive chemicals by virtueof a laser beam irradiation.
 24. The fault repairing method for a liquidcrystal display device according to claim 22 , wherein the spare thinfilm transistor is separated from the pixel electrode, a sourceelectrode of the spare thin film transistor and the pixel electrode areconnected by a laser welding in repairing the fault.
 25. The faultrepairing method for a liquid crystal display device according to claim22 , wherein contact holes are opened in an insulating film on the gateelectrode of a spare thin film transistor and on the gate bus line of aswitching thin film transistor, by laser beam irradiation before formingthe conductive pattern.
 26. The fault repairing method for a liquidcrystal display device according to claim 22 , wherein the conductivepattern is formed of any one metal selected from a group consisting oftungsten, molybdenum, chromium, gold, and silver.
 27. A liquid crystaldisplay device comprising: switching thin film transistors that areconnected to gate bus lines, data bus lines and pixel electrodes; andspare thin film transistors that are not connected to the gate buslines, wherein a part of the gate bus lines are provided as a gateelectrode of the spare thin film transistor.
 28. A liquid crystaldisplay device comprising: switching thin film transistors that areconnected to gate bus lines, data bus lines and pixel electrodes; andspare thin film transistors that are not connected to the gate buslines, wherein a gate electrode of the spare thin film transistor isarranged between the data bus line and the pixel electrode.
 29. A faultrepairing method for a liquid crystal display device that includes aplurality of bus lines formed on a substrate, TAB terminals arrangedalong a first side of the substrate and connected to the bus linesrespectively, and repair wirings arranged along a second side opposingto the first side, comprising the step of: forming at least a conductivepattern for connecting electrically a bus line and a repair wiring, inrepairing the fault.
 30. The fault repairing method for a liquid crystaldisplay device according to claim 29 , wherein the conductive pattern isformed by a laser CVD method or by baking conductive chemicals by virtueof a laser beam irradiation.
 31. The fault repairing method for a liquidcrystal display device according to claim 29 , wherein a plurality ofrepair wiring are provided.
 32. The fault repairing method for a liquidcrystal display device according to claim 29 , wherein contact holes areopened on the bus lines and the repair wirings, by laser beamirradiation before forming the conductive pattern.
 33. The faultrepairing method for a liquid crystal display device according to claim29 , wherein the conductive pattern is formed of any one metal selectedfrom a group consisting of tungsten, molybdenum, chromium, gold, andsilver.
 34. A liquid crystal display device comprising: a plurality offirst bus lines on a substrate; a plurality of second bus linesintersected with the plurality of first bus lines via an insulatingfilm; a plurality of TAB terminals arranged along a first side of thesubstrate and connected to the plurality of first bus linesrespectively; and repair wirings arranged along a second side opposingto the first side, the repair wirings having no wiring that intersectswith the repair wirings before a fault is repaired.
 35. A liquid crystaldisplay device comprising: a plurality of first bus lines on asubstrate; a plurality of second bus lines intersected with theplurality of first bus lines via an insulating film; a plurality of TABterminals arranged along a first side of the substrate and connected tothe plurality of first bus lines respectively; repair wirings arrangedalong a second side opposing to the first side; repair terminals of thefirst bus lines provided along the second side; first connecting padsexposed on the repair terminals and connected electrically to the repairterminals; and second connecting pads exposed on the repair wirings andconnected electrically to the repair wirings.
 36. The liquid crystaldisplay device according to claim 35 , wherein the repair wirings andthe first connecting pads are arranged on an outside of a color filtersubstrate opposing to the substrate for sealing liquid crystal betweenthem.
 37. The liquid crystal display device according to claim 35 ,wherein a repair TAB terminal is formed adjacently to the TAB terminals.38. The liquid crystal display device according to claim 37 , the repairTAB terminal is connected to the first bus line in repairing the fault.